{"kind":"web","tier":"cache","target":"redocly.com","scorecard_url":"https://anc.dev/score/redocly.com","markdown_url":"https://anc.dev/score/redocly.com/md","json_url":"https://anc.dev/score/redocly.com/json","freshness":{"cached":true,"scored_at":"2026-09-15T19:02:03.739Z","refresh_after":"2026-09-15T19:03:03.739Z"},"spec_version":"0.5.0","scorecard":{"schema_version":"0.4","spec_version":"0.5.0","target_url":"https://redocly.com/","mcp_endpoint":"https://redocly.com/mcp","mcp_discovery":[{"source":"/.well-known/mcp/server-card.json","endpoint":"https://redocly.com/mcp"}],"tool":{"name":"redocly.com","url":"https://redocly.com/"},"audience":null,"audit_profile":null,"site_type":null,"public_listing":true,"summary":{"pass":32,"noncompliant":0,"broken":4,"absent":7,"n_a":22,"skip":0,"error":0},"coverage_summary":{"must":{"total":4,"verified":3},"should":{"total":34,"verified":25},"may":{"total":5,"verified":4}},"score_pct":73,"score":{"relative":73,"global":56},"categories":[{"id":"discoverability","name":"Discoverability","passed":4,"counted":6},{"id":"content-for-agents","name":"Content for agents","passed":6,"counted":10},{"id":"bot-crawl-policy","name":"Bot & crawl policy","passed":2,"counted":3},{"id":"api","name":"API","passed":0,"counted":3},{"id":"mcp","name":"MCP","passed":18,"counted":19},{"id":"agent-discovery-auth","name":"Agent discovery & auth","passed":2,"counted":2}],"results":[{"id":"openapi","label":"An OpenAPI description is published","category":"api","group":"P2","layer":"web","keyword":"must","tier":"required","principle":"P2","status":"absent","evidence":"https://redocly.com/openapi.json -> 404 (status 404 not in [200])","result":"Not found (https://redocly.com/openapi.json -> 404 (status 404 not in [200]))","remediation":{"goal":"Publish an OpenAPI description so non-MCP agents can call your HTTP API","fix":"If your service exposes an HTTP/REST API (separate from any MCP endpoint), publish an OpenAPI\n3.1 description of it at `/openapi.json` (or `/openapi.yaml`, or `/.well-known/openapi.json`).\nNon-MCP agents use it to discover endpoints, parameters, and response shapes, and to generate\ntyped clients. A service whose only machine surface is MCP has no REST API to describe here.","skill_url":"https://anc.dev/fix/openapi","resources":[{"label":"OpenAPI 3.1","url":"https://spec.openapis.org/oas/latest.html"}],"evidence":"https://redocly.com/openapi.json -> 404 (status 404 not in [200])","prompt":"Goal: Publish an OpenAPI description so non-MCP agents can call your HTTP API\nFix: If your service exposes an HTTP/REST API (separate from any MCP endpoint), publish an OpenAPI 3.1 description of it at `/openapi.json` (or `/openapi.yaml`, or `/.well-known/openapi.json`). Non-MCP agents use it to discover endpoints, parameters, and response shapes, and to generate typed clients. A service whose only machine surface is MCP has no REST API to describe here.\nSkill: https://anc.dev/fix/openapi\nDocs: https://spec.openapis.org/oas/latest.html\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/openapi.json -> 404 (status 404 not in [200])\n--- end evidence ---"}},{"id":"mcp-initialize","label":"initialize handshake returns serverInfo + protocolVersion","category":"mcp","group":"P2","layer":"web","keyword":"must","tier":"required","principle":"P2","status":"pass","evidence":"serverInfo Docs MCP server, protocol 2025-06-18","result":"Verified (serverInfo Docs MCP server, protocol 2025-06-18)"},{"id":"mcp-server-discover","label":"server/discover answers with server identity on the modern lane","category":"mcp","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"pass","evidence":"supports 2026-07-28, serverInfo Docs MCP server","result":"Verified (supports 2026-07-28, serverInfo Docs MCP server)"},{"id":"llms-txt","label":"/llms.txt present with a summary and link index","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"pass","evidence":"https://redocly.com/llms.txt -> 200","result":"Verified (https://redocly.com/llms.txt -> 200)"},{"id":"llms-full-txt","label":"/llms-full.txt present (single-fetch full corpus)","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/llms-full.txt -> 404 (status 404 not in [200])","result":"Not implemented, optional (https://redocly.com/llms-full.txt -> 404 (status 404 not in [200]))"},{"id":"accept-markdown","label":"Accept text/markdown content negotiation returns markdown","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"absent","evidence":"https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","result":"Not found (https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/))","remediation":{"goal":"Honor Accept text/markdown on content URLs with raw markdown, not HTML chrome","fix":"Honor `Accept: text/markdown` on content URLs and return raw markdown rather than HTML chrome.\nAgents parse markdown far more reliably than a JS-rendered page. Serve the markdown twin at the\nsame URL via content negotiation, invisibly to crawlers.","skill_url":"https://anc.dev/fix/accept-markdown","resources":[{"label":"RFC 7763 (text/markdown)","url":"https://www.rfc-editor.org/rfc/rfc7763"}],"evidence":"https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","prompt":"Goal: Honor Accept text/markdown on content URLs with raw markdown, not HTML chrome\nFix: Honor `Accept: text/markdown` on content URLs and return raw markdown rather than HTML chrome. Agents parse markdown far more reliably than a JS-rendered page. Serve the markdown twin at the same URL via content negotiation, invisibly to crawlers.\nSkill: https://anc.dev/fix/accept-markdown\nDocs: https://www.rfc-editor.org/rfc/rfc7763\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)\n--- end evidence ---"}},{"id":"robots","label":"/robots.txt present","category":"discoverability","group":"P7","layer":"web","keyword":"should","tier":"recommended","principle":"P7","status":"pass","evidence":"https://redocly.com/robots.txt -> 200","result":"Verified (https://redocly.com/robots.txt -> 200)"},{"id":"sitemap","label":"/sitemap.xml present","category":"discoverability","group":"P7","layer":"web","keyword":"may","tier":"optional","principle":"P7","status":"pass","evidence":"https://redocly.com/sitemap.xml -> 200","result":"Verified (https://redocly.com/sitemap.xml -> 200)"},{"id":"oauth-discovery","label":"OAuth/OIDC discovery metadata published","category":"agent-discovery-auth","group":"P1","layer":"web","keyword":"may","tier":"optional","principle":"P1","status":"n_a","na_reason":"antecedent-unmet","evidence":"no auth surface detected","result":"Not applicable (no auth surface detected)"},{"id":"json-schemas","label":"Referenced JSON Schemas resolve as application/schema+json","category":"api","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"antecedent-unmet","evidence":"no JSON Schema references detected","result":"Not applicable (no JSON Schema references detected)"},{"id":"llms-full-txt-scoped","label":"Per-section llms-full.txt files resolve under content subdirectories","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"antecedent-unmet","evidence":"root llms-full.txt not present","result":"Not applicable (root llms-full.txt not present)"},{"id":"oauth-protected-resource","label":"OAuth Protected Resource Metadata published (RFC 9728)","category":"agent-discovery-auth","group":"P1","layer":"web","keyword":"may","tier":"optional","principle":"P1","status":"n_a","na_reason":"antecedent-unmet","evidence":"MCP endpoint does not challenge for auth","result":"Not applicable (MCP endpoint does not challenge for auth)"},{"id":"auth-md","label":"Agent auth/registration metadata doc published","category":"agent-discovery-auth","group":"P1","layer":"web","keyword":"may","tier":"optional","principle":"P1","status":"n_a","na_reason":"antecedent-unmet","evidence":"no auth surface detected","result":"Not applicable (no auth surface detected)"},{"id":"api-catalog","label":"/.well-known/api-catalog published (RFC 9727)","category":"api","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/.well-known/api-catalog -> 404 (status 404 not in [200])","result":"Not implemented, optional (https://redocly.com/.well-known/api-catalog -> 404 (status 404 not in [200]))"},{"id":"rate-limit-headers","label":"API responses advertise rate-limit headers","category":"api","group":"P6","layer":"web","keyword":"should","tier":"recommended","principle":"P6","status":"absent","evidence":"https://redocly.com/anc-web-audit-no-such-api -> 404 (no rate-limit header)","result":"Not found (https://redocly.com/anc-web-audit-no-such-api -> 404 (no rate-limit header))","remediation":{"goal":"Advertise remaining quota on API responses so agents can back off instead of retrying blindly","fix":"Send IETF RateLimit headers (`RateLimit-Limit`, `RateLimit-Remaining`, `RateLimit-Reset`) or\nthe common `X-RateLimit-*` aliases on API responses. A 429 should also carry `Retry-After`.\nWithout them an agent has no budget and will retry until it is locked out.","skill_url":"https://anc.dev/fix/rate-limit-headers","resources":[{"label":"IETF RateLimit header draft","url":"https://datatracker.ietf.org/doc/draft-ietf-httpapi-ratelimit-headers/"}],"evidence":"https://redocly.com/anc-web-audit-no-such-api -> 404 (no rate-limit header)","prompt":"Goal: Advertise remaining quota on API responses so agents can back off instead of retrying blindly\nFix: Send IETF RateLimit headers (`RateLimit-Limit`, `RateLimit-Remaining`, `RateLimit-Reset`) or the common `X-RateLimit-*` aliases on API responses. A 429 should also carry `Retry-After`. Without them an agent has no budget and will retry until it is locked out.\nSkill: https://anc.dev/fix/rate-limit-headers\nDocs: https://datatracker.ietf.org/doc/draft-ietf-httpapi-ratelimit-headers/\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/anc-web-audit-no-such-api -> 404 (no rate-limit header)\n--- end evidence ---"}},{"id":"json-errors","label":"API client errors return JSON, not HTML","category":"api","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"broken","evidence":"https://redocly.com/anc-web-audit-no-such-api -> 404 (HTML error body)","result":"Present but broken (https://redocly.com/anc-web-audit-no-such-api -> 404 (HTML error body))","remediation":{"goal":"Return a JSON error body on client-error API responses so agents can parse the failure","fix":"On a client-error API response (4xx), return `Content-Type: application/json` and a JSON object\n(for example `{ \"error\": { \"code\": \"not_found\", \"message\": \"...\" } }`), not an HTML error page.\nAgents cannot recover from a soft-HTML 404. The audit probes a documented OpenAPI 4xx GET when\none exists, otherwise `GET /anc-web-audit-no-such-api`.","skill_url":"https://anc.dev/fix/json-errors","resources":[{"label":"RFC 9457 (problem+json)","url":"https://www.rfc-editor.org/rfc/rfc9457"}],"evidence":"https://redocly.com/anc-web-audit-no-such-api -> 404 (HTML error body)","prompt":"Goal: Return a JSON error body on client-error API responses so agents can parse the failure\nFix: On a client-error API response (4xx), return `Content-Type: application/json` and a JSON object (for example `{ \"error\": { \"code\": \"not_found\", \"message\": \"...\" } }`), not an HTML error page. Agents cannot recover from a soft-HTML 404. The audit probes a documented OpenAPI 4xx GET when one exists, otherwise `GET /anc-web-audit-no-such-api`.\nSkill: https://anc.dev/fix/json-errors\nDocs: https://www.rfc-editor.org/rfc/rfc9457\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/anc-web-audit-no-such-api -> 404 (HTML error body)\n--- end evidence ---"}},{"id":"mcp-unknown-method","label":"unknown JSON-RPC method returns -32601","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32601","result":"Verified (error code -32601)"},{"id":"mcp-malformed-body","label":"a non-JSON body draws -32700 (or a typed HTTP 400/415 refusal)","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"broken","evidence":"https://redocly.com/mcp -> 500 (no parseable JSON-RPC response)","result":"Present but broken (https://redocly.com/mcp -> 500 (no parseable JSON-RPC response))","remediation":{"goal":"Refuse an unparseable request body with a parse-error envelope or a typed HTTP refusal","fix":"Answer a `POST` whose body is not valid JSON with the JSON-RPC parse-error envelope\n(`error.code: -32700`, `id: null`); delivering it at HTTP `400` is fine. A bare HTTP `400`\nor `415` with no envelope also conforms as a typed refusal. What fails the check: a `200`\nwith garbage, a hang, or any other bare status (a bare `404` reads as a dead endpoint, not\na refusal).","skill_url":"https://anc.dev/fix/mcp-malformed-body","resources":[{"label":"JSON-RPC 2.0","url":"https://www.jsonrpc.org/specification#error_object"}],"evidence":"https://redocly.com/mcp -> 500 (no parseable JSON-RPC response)","prompt":"Goal: Refuse an unparseable request body with a parse-error envelope or a typed HTTP refusal\nFix: Answer a `POST` whose body is not valid JSON with the JSON-RPC parse-error envelope (`error.code: -32700`, `id: null`); delivering it at HTTP `400` is fine. A bare HTTP `400` or `415` with no envelope also conforms as a typed refusal. What fails the check: a `200` with garbage, a hang, or any other bare status (a bare `404` reads as a dead endpoint, not a refusal).\nSkill: https://anc.dev/fix/mcp-malformed-body\nDocs: https://www.jsonrpc.org/specification#error_object\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/mcp -> 500 (no parseable JSON-RPC response)\n--- end evidence ---"}},{"id":"mcp-resources-list","label":"resources/list returns at least one resource when advertised","category":"mcp","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"pass","evidence":"https://redocly.com/mcp -> 200","result":"Verified (https://redocly.com/mcp -> 200)"},{"id":"mcp-tools-list","label":"tools/list returns a tools array with input schemas","category":"mcp","group":"P2","layer":"web","keyword":"must","tier":"required","principle":"P2","status":"pass","evidence":"2 tools, 2 with input schema","result":"Verified (2 tools, 2 with input schema)"},{"id":"mcp-batch-reject","label":"a batch carrying a modern-envelope request is rejected -32600","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32600","result":"Verified (error code -32600)"},{"id":"mcp-modern-tools-list","label":"header-routed tools/list (2026-07-28) returns tools without initialize","category":"mcp","group":"P2","layer":"web","keyword":"must","tier":"required","principle":"P2","status":"pass","evidence":"2 tools, 2 with input schema","result":"Verified (2 tools, 2 with input schema)"},{"id":"mcp-capabilities","label":"initialize advertises capabilities (tools / resources / prompts)","category":"mcp","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"pass","evidence":"serverInfo Docs MCP server, protocol 2025-06-18","result":"Verified (serverInfo Docs MCP server, protocol 2025-06-18)"},{"id":"mcp-modern-header-mismatch","label":"an Mcp-Method header disagreeing with the body method draws -32020","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32020","result":"Verified (error code -32020)"},{"id":"mcp-unknown-tool","label":"tools/call with an unknown tool name returns -32602","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32602","result":"Verified (error code -32602)"},{"id":"mcp-modern-unknown-method","label":"an unknown method on the modern lane returns -32601","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32601","result":"Verified (error code -32601)"},{"id":"mcp-modern-resources-miss","label":"modern resources/read with an unknown URI returns -32602","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32602","result":"Verified (error code -32602)"},{"id":"mcp-modern-version-reject","label":"an unsupported protocol version is rejected -32022 with data.supported","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32022","result":"Verified (error code -32022)"},{"id":"mcp-modern-clientcaps","label":"_meta missing clientCapabilities is rejected (-32602 or -32600)","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"error code -32602","result":"Verified (error code -32602)"},{"id":"mcp-accept-json","label":"a JSON-only Accept is answered without SSE framing","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"https://redocly.com/mcp -> 406","result":"Verified (https://redocly.com/mcp -> 406)"},{"id":"mcp-get-fast-fail","label":"GET on the MCP endpoint answers fast (not a held-open hang)","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"https://redocly.com/mcp -> 405","result":"Verified (https://redocly.com/mcp -> 405)"},{"id":"well-known-mcp-card","label":"A .well-known MCP server card is published (SEP-1649)","category":"mcp","group":"P8","layer":"web","keyword":"should","tier":"recommended","principle":"P8","status":"pass","evidence":"https://redocly.com/.well-known/mcp/server-card.json -> 200","result":"Verified (https://redocly.com/.well-known/mcp/server-card.json -> 200)"},{"id":"webmcp","label":"Root HTML exposes WebMCP browser tools","category":"mcp","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/ -> 200 (no WebMCP markers in root HTML)","result":"Not implemented, optional (https://redocly.com/ -> 200 (no WebMCP markers in root HTML))"},{"id":"llms-txt-format","label":"llms.txt has H1, summary, and a link index","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"pass","evidence":"https://redocly.com/llms.txt -> error","result":"Verified (https://redocly.com/llms.txt -> error)"},{"id":"mcp-accept-unsatisfiable","label":"an unsatisfiable Accept draws a 406 rather than an unasked-for type","category":"mcp","group":"P4","layer":"web","keyword":"should","tier":"recommended","principle":"P4","status":"pass","evidence":"https://redocly.com/mcp -> 406","result":"Verified (https://redocly.com/mcp -> 406)"},{"id":"llms-txt-when-to-use","label":"llms.txt has a when-to-use or programmatic-access section","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"absent","evidence":"https://redocly.com/llms.txt -> error (no when-to-use heading)","result":"Not found (https://redocly.com/llms.txt -> error (no when-to-use heading))","remediation":{"goal":"Tell agents when to use the MCP or docs from a short llms.txt heading","fix":"Add a heading such as `## When to use` or `## Programmatic access` with a few lines on when\nan agent should connect (for example: \"Use the MCP when you need to search or score a CLI\").\nThe audit looks for that heading; it does not grade the prose with an LLM.","skill_url":"https://anc.dev/fix/llms-txt-when-to-use","resources":[{"label":"llmstxt.org","url":"https://llmstxt.org/"}],"evidence":"https://redocly.com/llms.txt -> error (no when-to-use heading)","prompt":"Goal: Tell agents when to use the MCP or docs from a short llms.txt heading\nFix: Add a heading such as `## When to use` or `## Programmatic access` with a few lines on when an agent should connect (for example: \"Use the MCP when you need to search or score a CLI\"). The audit looks for that heading; it does not grade the prose with an LLM.\nSkill: https://anc.dev/fix/llms-txt-when-to-use\nDocs: https://llmstxt.org/\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/llms.txt -> error (no when-to-use heading)\n--- end evidence ---"}},{"id":"mcp-cors-preflight","label":"CORS preflight (OPTIONS) succeeds with Access-Control-Allow-* headers","category":"mcp","group":"P6","layer":"web","keyword":"should","tier":"recommended","principle":"P6","status":"n_a","na_reason":"posture-consistent","evidence":"no Allow-Origin on the preflight or the POST: consistent no-CORS posture","result":"Deliberate posture, not scored (no Allow-Origin on the preflight or the POST: consistent no-CORS posture)"},{"id":"mcp-cors-actual","label":"POST response carries Access-Control-Allow-Origin","category":"mcp","group":"P6","layer":"web","keyword":"should","tier":"recommended","principle":"P6","status":"n_a","na_reason":"posture-consistent","evidence":"no Allow-Origin on the preflight or the POST: consistent no-CORS posture","result":"Deliberate posture, not scored (no Allow-Origin on the preflight or the POST: consistent no-CORS posture)"},{"id":"markdown-cli-ua","label":"Bare CLI User-Agent receives the markdown twin","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","result":"Not implemented, optional (https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/))"},{"id":"markdown-agent-ua","label":"AI user-fetch User-Agent receives the markdown twin","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","result":"Not implemented, optional (https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/))"},{"id":"agent-ua-reachable","label":"AI user-fetch User-Agent can reach the homepage","category":"bot-crawl-policy","group":"P7","layer":"web","keyword":"should","tier":"recommended","principle":"P7","status":"pass","evidence":"https://redocly.com/ -> 200","result":"Verified (https://redocly.com/ -> 200)"},{"id":"markdown-vary","label":"Negotiated responses carry Vary Accept, User-Agent","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"absent","evidence":"https://redocly.com/ -> 200 (header vary no match /(?=.*accept(?!-))(?=.*user-agent)/)","result":"Not found (https://redocly.com/ -> 200 (header vary no match /(?=.*accept(?!-))(?=.*user-agent)/))","remediation":{"goal":"Emit Vary Accept, User-Agent so shared caches never serve one client the wrong variant","fix":"When the same URL serves HTML or markdown depending on the request, emit\n`Vary: Accept, User-Agent` on every response. Without it a shared cache (a CDN or a corporate\nproxy) can store the markdown twin under the bare URL and then hand it to a browser, or vice\nversa. Listing both request headers you negotiate on tells every cache to key its stored copies\nby them, so each client class gets the variant it asked for. If the CDN ignores or strips Vary\n(Cloudflare's zone cache historically keeps only `Accept-Encoding`), do not give that cache a\nlong `s-maxage` on negotiated responses — otherwise HIT replies reach clients with no Vary and\nthe check still fails.","skill_url":"https://anc.dev/fix/markdown-vary","resources":[{"label":"RFC 9110 (Vary)","url":"https://www.rfc-editor.org/rfc/rfc9110#name-vary"}],"evidence":"https://redocly.com/ -> 200 (header vary no match /(?=.*accept(?!-))(?=.*user-agent)/)","prompt":"Goal: Emit Vary Accept, User-Agent so shared caches never serve one client the wrong variant\nFix: When the same URL serves HTML or markdown depending on the request, emit `Vary: Accept, User-Agent` on every response. Without it a shared cache (a CDN or a corporate proxy) can store the markdown twin under the bare URL and then hand it to a browser, or vice versa. Listing both request headers you negotiate on tells every cache to key its stored copies by them, so each client class gets the variant it asked for. If the CDN ignores or strips Vary (Cloudflare's zone cache historically keeps only `Accept-Encoding`), do not give that cache a long `s-maxage` on negotiated responses — otherwise HIT replies reach clients with no Vary and the check still fails.\nSkill: https://anc.dev/fix/markdown-vary\nDocs: https://www.rfc-editor.org/rfc/rfc9110#name-vary\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/ -> 200 (header vary no match /(?=.*accept(?!-))(?=.*user-agent)/)\n--- end evidence ---"}},{"id":"markdown-accept-plain","label":"Accept text/plain returns the markdown twin","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","result":"Not implemented, optional (https://redocly.com/ -> 200 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/))"},{"id":"root-meta-description","label":"Root HTML has a descriptive <meta name=\"description\">","category":"content-for-agents","group":"P3","layer":"web","keyword":"should","tier":"recommended","principle":"P3","status":"pass","evidence":"https://redocly.com/ -> 200","result":"Verified (https://redocly.com/ -> 200)"},{"id":"schema-org-jsonld","label":"Root HTML embeds Schema.org JSON-LD","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/ -> 200 (body no match /application/ld\\+json/)","result":"Not implemented, optional (https://redocly.com/ -> 200 (body no match /application/ld\\+json/))"},{"id":"markdown-frontmatter","label":"Markdown twin carries YAML frontmatter","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/ -> 200 (root served HTML, not a markdown twin)","result":"Not implemented, optional (https://redocly.com/ -> 200 (root served HTML, not a markdown twin))"},{"id":"semantic-html","label":"Root HTML uses semantic landmarks","category":"content-for-agents","group":"P3","layer":"web","keyword":"may","tier":"optional","principle":"P3","status":"pass","evidence":"https://redocly.com/ -> 200","result":"Verified (https://redocly.com/ -> 200)"},{"id":"noscript-fallback","label":"Root HTML has a <noscript> with machine entry points","category":"content-for-agents","group":"P1","layer":"web","keyword":"should","tier":"recommended","principle":"P1","status":"pass","evidence":"https://redocly.com/ -> 200","result":"Verified (https://redocly.com/ -> 200)"},{"id":"agent-friendly-404","label":"Unknown paths return HTTP 404 or 410","category":"discoverability","group":"P8","layer":"web","keyword":"should","tier":"recommended","principle":"P8","status":"pass","evidence":"https://redocly.com/anc-web-audit-no-such-page -> 404","result":"Verified (https://redocly.com/anc-web-audit-no-such-page -> 404)"},{"id":"mcp-card-legacy-aliases","label":"Legacy MCP card paths redirect to the canonical card","category":"mcp","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/.well-known/mcp -> 404 (404 alias not published)","result":"Not implemented, optional (https://redocly.com/.well-known/mcp -> 404 (404 alias not published))"},{"id":"link-headers","label":"Homepage sends RFC 8288 Link headers pointing at agent resources","category":"discoverability","group":"P3","layer":"web","keyword":"should","tier":"recommended","principle":"P3","status":"absent","evidence":"https://redocly.com/ -> 200 (header link no match /rel=\"?(service-desc|describedby|api-catalog|service-doc)\"?/)","result":"Not found (https://redocly.com/ -> 200 (header link no match /rel=\"?(service-desc|describedby|api-catalog|service-doc)\"?/))","remediation":{"goal":"Advertise machine surfaces in a Link response header on / for header-only discovery","fix":"Send a `Link` response header on `/` (RFC 8288) whose `rel` points at your machine surfaces, so an\nagent reading only response headers finds them without parsing HTML or probing `/.well-known`. Use\nthe RFC 8631 service trio and the RFC 9727 catalog: `rel=\"service-desc\"` at a machine-readable\ndescription (OpenAPI, or an MCP server card), `rel=\"service-doc\"` at the human-readable doc,\n`rel=\"service-meta\"` at the service-context declaration, and `rel=\"api-catalog\"` at your\n`/.well-known/api-catalog` index. Example:\n`Link: </.well-known/api-catalog>; rel=\"api-catalog\", </.well-known/mcp/server-card.json>; rel=\"service-desc\"`.","skill_url":"https://anc.dev/fix/link-headers","resources":[{"label":"RFC 8288 (Link)","url":"https://www.rfc-editor.org/rfc/rfc8288"},{"label":"RFC 8631 (service links)","url":"https://www.rfc-editor.org/rfc/rfc8631"},{"label":"RFC 9727 (api-catalog)","url":"https://www.rfc-editor.org/rfc/rfc9727"}],"evidence":"https://redocly.com/ -> 200 (header link no match /rel=\"?(service-desc|describedby|api-catalog|service-doc)\"?/)","prompt":"Goal: Advertise machine surfaces in a Link response header on / for header-only discovery\nFix: Send a `Link` response header on `/` (RFC 8288) whose `rel` points at your machine surfaces, so an agent reading only response headers finds them without parsing HTML or probing `/.well-known`. Use the RFC 8631 service trio and the RFC 9727 catalog: `rel=\"service-desc\"` at a machine-readable description (OpenAPI, or an MCP server card), `rel=\"service-doc\"` at the human-readable doc, `rel=\"service-meta\"` at the service-context declaration, and `rel=\"api-catalog\"` at your `/.well-known/api-catalog` index. Example: `Link: </.well-known/api-catalog>; rel=\"api-catalog\", </.well-known/mcp/server-card.json>; rel=\"service-desc\"`.\nSkill: https://anc.dev/fix/link-headers\nDocs: https://www.rfc-editor.org/rfc/rfc8288, https://www.rfc-editor.org/rfc/rfc8631, https://www.rfc-editor.org/rfc/rfc9727\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/ -> 200 (header link no match /rel=\"?(service-desc|describedby|api-catalog|service-doc)\"?/)\n--- end evidence ---"}},{"id":"root-link-rel","label":"Root HTML links to machine surfaces via <link rel>","category":"discoverability","group":"P3","layer":"web","keyword":"should","tier":"recommended","principle":"P3","status":"pass","evidence":"https://redocly.com/ -> 200","result":"Verified (https://redocly.com/ -> 200)"},{"id":"content-without-js","label":"Root HTML has an H1 and readable text without JavaScript","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"n_a","evidence":"no h1 in raw HTML; visible text 4477 chars (min 200)","result":"Not applicable (no h1 in raw HTML; visible text 4477 chars (min 200))"},{"id":"dns-aid","label":"DNS for AI Discovery (DNS-AID) records under _agents (IETF draft)","category":"discoverability","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"n_a","na_reason":"optional-absent","evidence":"no DNS-AID records","result":"Not implemented, optional (no DNS-AID records)"},{"id":"robots-ai-rules","label":"robots.txt declares AI-crawler rules (RFC 9309)","category":"bot-crawl-policy","group":"P7","layer":"web","keyword":"should","tier":"recommended","principle":"P7","status":"pass","evidence":"https://redocly.com/robots.txt -> 200","result":"Verified (https://redocly.com/robots.txt -> 200)"},{"id":"content-signals","label":"robots.txt declares Content-Signal AI-usage preferences","category":"bot-crawl-policy","group":"P7","layer":"web","keyword":"should","tier":"recommended","principle":"P7","status":"broken","evidence":"https://redocly.com/robots.txt -> 200 (body no match /^\\s*Content-Signal:\\s*(ai-train|search|ai-input)/)","result":"Present but broken (https://redocly.com/robots.txt -> 200 (body no match /^\\s*Content-Signal:\\s*(ai-train|search|ai-input)/))","remediation":{"goal":"Declare Content-Signal AI-usage preferences in robots.txt","fix":"Add `Content-Signal` directives to `robots.txt` (contentsignals.org): `ai-train`, `search`,\nand `ai-input` set to `yes` or `no`. They express usage preferences at a finer grain than a\nblanket allow/deny.","skill_url":"https://anc.dev/fix/content-signals","resources":[{"label":"contentsignals.org","url":"https://contentsignals.org/"}],"evidence":"https://redocly.com/robots.txt -> 200 (body no match /^\\s*Content-Signal:\\s*(ai-train|search|ai-input)/)","prompt":"Goal: Declare Content-Signal AI-usage preferences in robots.txt\nFix: Add `Content-Signal` directives to `robots.txt` (contentsignals.org): `ai-train`, `search`, and `ai-input` set to `yes` or `no`. They express usage preferences at a finer grain than a blanket allow/deny.\nSkill: https://anc.dev/fix/content-signals\nDocs: https://contentsignals.org/\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/robots.txt -> 200 (body no match /^\\s*Content-Signal:\\s*(ai-train|search|ai-input)/)\n--- end evidence ---"}},{"id":"agent-friendly-404-md","label":"404 body is markdown with a recovery link","category":"discoverability","group":"P8","layer":"web","keyword":"should","tier":"recommended","principle":"P8","status":"absent","evidence":"https://redocly.com/anc-web-audit-no-such-page -> 404 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","result":"Not found (https://redocly.com/anc-web-audit-no-such-page -> 404 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/))","remediation":{"goal":"Serve a short markdown 404 that links at least one agent recovery surface","fix":"When `Accept: text/markdown` hits an unknown path, return 404 or 410 with a short markdown\nbody that includes at least one recovery link: sitemap, `llms.txt`, a docs index, or an\nequivalent same-origin href. Linking both sitemap and `llms.txt` as absolute URLs is the\nstronger pattern. Zero links is a miss even when the status is correct.","skill_url":"https://anc.dev/fix/agent-friendly-404-md","resources":[{"label":"llmstxt.org","url":"https://llmstxt.org/"}],"evidence":"https://redocly.com/anc-web-audit-no-such-page -> 404 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)","prompt":"Goal: Serve a short markdown 404 that links at least one agent recovery surface\nFix: When `Accept: text/markdown` hits an unknown path, return 404 or 410 with a short markdown body that includes at least one recovery link: sitemap, `llms.txt`, a docs index, or an equivalent same-origin href. Linking both sitemap and `llms.txt` as absolute URLs is the stronger pattern. Zero links is a miss even when the status is correct.\nSkill: https://anc.dev/fix/agent-friendly-404-md\nDocs: https://llmstxt.org/\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/anc-web-audit-no-such-page -> 404 (content-type \"text/html; charset=UTF-8\" !~ /markdown|text/plain/)\n--- end evidence ---"}},{"id":"mcp-usage-doc","label":"A human/agent usage doc for the server resolves","category":"mcp","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/mcp-skill.md -> 404 (status 404 not in [200])","result":"Not implemented, optional (https://redocly.com/mcp-skill.md -> 404 (status 404 not in [200]))"},{"id":"web-bot-auth","label":"Web Bot Auth signature directory present (informational)","category":"bot-crawl-policy","group":"P6","layer":"web","keyword":"may","tier":"optional","principle":"P6","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/.well-known/http-message-signatures-directory -> 404 (status 404 not in [200])","result":"Not implemented, optional (https://redocly.com/.well-known/http-message-signatures-directory -> 404 (status 404 not in [200]))"},{"id":"a2a-agent-card","label":"A2A Agent Card published for agent-to-agent discovery","category":"agent-discovery-auth","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"pass","evidence":"https://redocly.com/.well-known/agent-card.json -> 200","result":"Verified (https://redocly.com/.well-known/agent-card.json -> 200)"},{"id":"security-txt","label":"/.well-known/security.txt present (RFC 9116)","category":"bot-crawl-policy","group":"P4","layer":"web","keyword":"may","tier":"optional","principle":"P4","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/.well-known/security.txt -> 404 (status 404 not in [200])","result":"Not implemented, optional (https://redocly.com/.well-known/security.txt -> 404 (status 404 not in [200]))"},{"id":"agent-skills","label":"Agent-skills discovery index published","category":"agent-discovery-auth","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"pass","evidence":"https://redocly.com/.well-known/agent-skills/index.json -> 200","result":"Verified (https://redocly.com/.well-known/agent-skills/index.json -> 200)"},{"id":"ai-catalog","label":"/.well-known/ai-catalog.json published (ARD)","category":"agent-discovery-auth","group":"P8","layer":"web","keyword":"may","tier":"optional","principle":"P8","status":"n_a","na_reason":"optional-absent","evidence":"https://redocly.com/.well-known/ai-catalog.json -> 404 (status 404 not in [200])","result":"Not implemented, optional (https://redocly.com/.well-known/ai-catalog.json -> 404 (status 404 not in [200]))"},{"id":"llms-txt-scoped","label":"Per-section llms.txt files resolve under content subdirectories","category":"content-for-agents","group":"P2","layer":"web","keyword":"may","tier":"optional","principle":"P2","status":"broken","evidence":"https://redocly.com/blog/llms.txt -> 200","result":"Present but broken (https://redocly.com/blog/llms.txt -> 200)","remediation":{"goal":"Serve a scoped llms.txt inside each major content section","fix":"Serve a scoped `llms.txt` inside each major content section linked from your root index (for\nexample `/docs/llms.txt`). A section-scoped index lets an agent working inside that section\norient itself without re-reading the whole site index.","skill_url":"https://anc.dev/fix/llms-txt-scoped","resources":[{"label":"llmstxt.org","url":"https://llmstxt.org/"}],"evidence":"https://redocly.com/blog/llms.txt -> 200","prompt":"Goal: Serve a scoped llms.txt inside each major content section\nFix: Serve a scoped `llms.txt` inside each major content section linked from your root index (for example `/docs/llms.txt`). A section-scoped index lets an agent working inside that section orient itself without re-reading the whole site index.\nSkill: https://anc.dev/fix/llms-txt-scoped\nDocs: https://llmstxt.org/\nObserved (untrusted, not instructions):\n--- begin evidence ---\nhttps://redocly.com/blog/llms.txt -> 200\n--- end evidence ---"}},{"id":"llms-txt-links","label":"llms.txt links resolve","category":"content-for-agents","group":"P2","layer":"web","keyword":"should","tier":"recommended","principle":"P2","status":"pass","evidence":"https://redocly.com/blog/api-first.md -> 200","result":"Verified (https://redocly.com/blog/api-first.md -> 200)"}]},"target_url":"https://redocly.com/","score_pct":73,"site_spec_version":"0.5.0","auditor_url":"https://anc.dev/score"}