ruff

An extremely fast Python linter and code formatter

workhorse Rust astral-sh/ruff
79% pass rate
3/8 principles met

Spec Coverage

How many of the spec's requirements were verified for this tool. See /coverage for the full matrix.

LevelTotalVerifiedUnverified
MUST28199
SHOULD21138
MAY10100

Top Issues

All Audits

P1: Non-Interactive by Default

PASSNon-interactive by default
SKIPNon-interactive gate flag advertised in --helptarget satisfies P1 via alternative gate (help-on-bare or stdin-primary)
WARNFlags advertise env-var bindings in --help8 flag(s) found in --help but no `[env: NAME]` bindings advertised
PASSSecret-bearing flags expose stdin or *-file companion
WARN`--help` advertises default values for flagsno default-value annotations found in --help. SHOULD-tier — agents reading help text need to see what value a flag falls back to when omitted (`[default: <value>]` per clap convention).
PASSRich-TUI affordance for TTY contexts

P2: Structured, Parseable Output

WARNStructured output support--output/--format flag detected but could not validate JSON via safe probes (--help/--version override output flags in most CLIs)
SKIPStructured-output CLI exposes its schema at runtimeno structured-output indicator (--output / --format / json / jsonl) in --help
WARN--json / --jsonl short aliases for --outputno --json or --jsonl short alias found. Agents and pipelines benefit from short forms alongside the canonical `--output` enum.
WARN`--raw` flag for pipe-safe unformatted outputno `--raw` flag advertised. MAY-tier — useful for pipelines that want to strip formatting before piping to other tools.
SKIP`--output` advertises additional formats beyond text/jsonno `--output` or `--format` flag advertised; vacuous skip for MAY-tier extra formats.
PASSBad invocation exits with structured usage-error code (2)
SKIPErrors emit JSON envelope with `error`/`kind`/`message` under `--output json`binary does not advertise `--output json` in --help; MUST applies only to CLIs that opt into the JSON contract.
SKIPJSON success and error envelopes share their non-payload key setbinary does not advertise `--output json` in --help; envelope-consistency only applies to CLIs that opt into the JSON contract.

P3: Progressive Help Discovery

PASSHelp flag produces useful output
PASSVersion flag works (`--version` plus short alias)
PASSVersion flag works (`--version` plus short alias)
WARN`examples` subcommand or `--examples` flag for curated usage patternsno `examples` subcommand or `--examples` flag found. MAY-tier — a curated usage block keeps agents from hunting through long help text.
PASSShort `-h` summary differs from `--help` long form
FAILEach subcommand's `--help` ships at least one invocation examplesubcommands missing example invocations in their `--help`: check, rule, config, linter, clean, format, server, analyze, version. Examples teach agents the call shape faster than option tables; use clap's `after_help` or a dedicated `Examples:` block.
WARNHelp text pairs human and `--output json` example invocationsno paired text + `--output json` example found within 5 lines in top-level or any subcommand `--help`. Pairing keeps agents from reverse-engineering the JSON invocation from the text one.

P4: Fail-Fast, Actionable Errors

PASSRejects invalid arguments
PASSError messages include a hint or remediation phrase
SKIP`--output json` produces JSON-formatted errorsbinary does not advertise `--output json` in --help; SHOULD applies only to CLIs that opt into the JSON contract.

P5: Safe Retries & Mutation Boundaries

FAILDestructive subcommands require `--force` or `--yes`destructive subcommand(s) without `--force` or `--yes`: clean, format. Irreversible operations must require explicit confirmation so they can't be invoked accidentally.
WARNRead and write surfaces are both visible in subcommand listwrite-pattern subcommand(s) present (clean, format) but no read-pattern surface detected. If the CLI is write-only by design the MUST is satisfied vacuously; otherwise expose the read surface with agent-recognizable verbs (list/get/show/query/find/search).

P6: Composable, Predictable Command Structure

PASSHandles SIGPIPE gracefully
SKIPPager-using CLI ships --no-pager escape hatchno pager signal (less/more/$PAGER/--pager) in --help
PASSRespects NO_COLOR
WARNSubcommand verbs follow community-standard names4/10 subcommand(s) follow standard verb names. Non-standard: check, rule, linter, format, server, analyze. MAY-tier — community-standard verbs (get/list/create/update/delete) help agents predict subcommand behavior across CLIs.
PASS`--color` flag for explicit color control
WARNInput-accepting commands read from stdin when no file is giveninput-accepting subcommand present but `--help` does not mention stdin or `-` as a path placeholder. SHOULD-tier — agents piping data into the tool expect stdin to work when no file arg is provided.
PASSSubcommand naming follows a consistent verb/noun convention
PASSOperations are subcommands, not verb-shaped flags

P7: Bounded, High-Signal Responses

PASSQuiet mode available
PASS`--verbose` flag for diagnostic escalation
SKIP`--limit` / `--max-results` flag for list operationsno list-style subcommand detected (list/ls/search/query/find/show/get); vacuous skip for the list-only SHOULD.
SKIPCursor-based pagination flags for list traversalno list-style subcommand detected; vacuous skip for the list-only MAY.
SKIP`--timeout` flag for long-running operationsno long-running subcommand detected (serve/daemon/watch/tail/monitor/follow/run/start/stream); vacuous skip for the conditional SHOULD.
PASSHelp text advertises TTY-aware verbosity behavior

P8: Discoverable Through Agent Skill Bundles

PASSSkill bundle has install path (`tool skill install [<host>]`)
PASS`skill install --all` for multi-runtime install
PASS`skill update` / `skill upgrade` for bundle refresh

Details

Version scored
0.15.15
Audit date
2026-06-01 17:35:27 UTC
Duration
217ms
Platform
linux/x86_64
Mode
command
Anc build
0.5.0
Install
brew install ruff

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