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.

Level Total Verified Unverified
MUST 28 19 9
SHOULD 21 13 8
MAY 10 10 0

Top Issues

All Audits

P1: Non-Interactive by Default

PASS Non-interactive by default
SKIP Non-interactive gate flag advertised in --help target satisfies P1 via alternative gate (help-on-bare or stdin-primary)
WARN Flags advertise env-var bindings in --help 8 flag(s) found in --help but no `[env: NAME]` bindings advertised
PASS Secret-bearing flags expose stdin or *-file companion
WARN `--help` advertises default values for flags no 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).
PASS Rich-TUI affordance for TTY contexts

P2: Structured, Parseable Output

WARN Structured output support --output/--format flag detected but could not validate JSON via safe probes (--help/--version override output flags in most CLIs)
SKIP Structured-output CLI exposes its schema at runtime no structured-output indicator (--output / --format / json / jsonl) in --help
WARN --json / --jsonl short aliases for --output no --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 output no `--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/json no `--output` or `--format` flag advertised; vacuous skip for MAY-tier extra formats.
PASS Bad invocation exits with structured usage-error code (2)
SKIP Errors 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.
SKIP JSON success and error envelopes share their non-payload key set binary does not advertise `--output json` in --help; envelope-consistency only applies to CLIs that opt into the JSON contract.

P3: Progressive Help Discovery

PASS Help flag produces useful output
PASS Version flag works (`--version` plus short alias)
PASS Version flag works (`--version` plus short alias)
WARN `examples` subcommand or `--examples` flag for curated usage patterns no `examples` subcommand or `--examples` flag found. MAY-tier — a curated usage block keeps agents from hunting through long help text.
PASS Short `-h` summary differs from `--help` long form
FAIL Each subcommand's `--help` ships at least one invocation example subcommands 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.
WARN Help text pairs human and `--output json` example invocations no 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

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

P5: Safe Retries & Mutation Boundaries

FAIL Destructive 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.
WARN Read and write surfaces are both visible in subcommand list write-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

PASS Handles SIGPIPE gracefully
SKIP Pager-using CLI ships --no-pager escape hatch no pager signal (less/more/$PAGER/--pager) in --help
PASS Respects NO_COLOR
WARN Subcommand verbs follow community-standard names 4/10 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
WARN Input-accepting commands read from stdin when no file is given input-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.
PASS Subcommand naming follows a consistent verb/noun convention
PASS Operations are subcommands, not verb-shaped flags

P7: Bounded, High-Signal Responses

PASS Quiet mode available
PASS `--verbose` flag for diagnostic escalation
SKIP `--limit` / `--max-results` flag for list operations no list-style subcommand detected (list/ls/search/query/find/show/get); vacuous skip for the list-only SHOULD.
SKIP Cursor-based pagination flags for list traversal no list-style subcommand detected; vacuous skip for the list-only MAY.
SKIP `--timeout` flag for long-running operations no long-running subcommand detected (serve/daemon/watch/tail/monitor/follow/run/start/stream); vacuous skip for the conditional SHOULD.
PASS Help text advertises TTY-aware verbosity behavior

P8: Discoverable Through Agent Skill Bundles

PASS Skill 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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