Conciseness

Every line carries non-obvious operational knowledge Claude could not infer ("Do not use `bk job log` — it hangs indefinitely", "`slack_send_message` does NOT support markdown tables", chunk limit "under 4800 chars"). No concept explanations or padding; it assumes competence and matches anchor 5 ("lean and efficient; every token earns its place") rather than anchor 4's "minor instances of over-explanation".

Actionability

Copy-paste ready commands with variants (`bun run ci:slowest 47324 100`, `--json`), exact fallback commands (`gh pr list --state merged --limit 10 --json number,headRefName`, `bk build list --branch <headRefName>`), a concrete gist command, and a fully specified output row format. Anchor 5 ("fully executable; covers the common cases") fits.

Workflow Clarity

Two clearly sequenced phases with explicit gating ("only if a channel was given") and a numbered Slack procedure. An error-recovery feedback loop exists for the primary failure mode ("If the script can't find a build automatically... pick one yourself" with exact commands), and chunk posting is ordered ("Post chunks sequentially so they stay ordered"). This matches anchor 5 ("clear sequence... feedback loops for error recovery"); the destructive/batch cap does not apply since this is read-only data gathering plus non-destructive posting with recovery paths.

Progressive Disclosure

The body is under 50 lines, well-sectioned (Gather the data / Post to Slack), and needs no external reference files — close to the simple-skill ideal of a 5. It drops to 4 because it references "the script (`scripts/ci-slowest-tests.ts`)" while no scripts/ directory (or any bundle file) exists in the skill, leaving a dangling path that the reader cannot resolve.

Specificity

"Find the top-N slowest test files in CI from a recent BuildKite run, optionally posting the results to a Slack channel as a formatted table" names two concrete, specific actions with exact technologies (BuildKite, Slack, top-N, formatted table). Not a 5 because coverage is limited to those two actions with no mention of other capabilities (e.g., JSON output or build selection) — anchor 4 ("several specific actions; minor gaps") is the closest fit; it clearly exceeds anchor 3's 1-2 partially-specified actions.

Completeness

The 'what' is explicit (find top-N slowest test files from a BuildKite run; optionally post to Slack as a formatted table) and the 'when' is explicit with concrete trigger phrases ("find slow CI tests", "what's making CI slow", "post a slow-test report to Slack"), matching anchor 5 exactly.

Trigger Term Quality

"Use when asked to find slow CI tests, 'what's making CI slow', or to post a slow-test report to Slack" includes natural user phrasing, even a colloquial quoted phrase. A few common synonyms are missing (e.g., "test suite is slow", "long-running tests", "CI duration"), so it matches anchor 4 ("good keyword coverage; a few natural terms missing") rather than anchor 5's comprehensive synonym/extension coverage.

Distinctiveness Conflict Risk

"top-N slowest test files in CI from a recent BuildKite run" carves a clear niche with distinct triggers; minimal overlap risk with generic test or Slack skills, matching anchor 5 ("clear niche with distinct triggers; minimal conflict risk"). Anchor 4 would require noticeable overlap with closely related skills, which is not the case.