Conciseness

Efficient and competence-assuming — no explanations of what asyncio, PRs, or CI gates are — with operational density throughout ("Match by the stable key (path, function, symbol) — line numbers shift after edits, so never compare by line"). Not 5 because of minor duplication: the same-file reachability caveat is stated twice (Step 0's "One residual blind spot remains" and Step 1's "Cross-file caveat"), and the batching-policy paragraph could be trimmed without losing its rules.

Actionability

Fully executable, copy-paste-ready commands for every mode and checkpoint: "uv run --project backend python scripts/scan_changed_blocking_io.py --base origin/main", "make detect-blocking-io", "cd backend && make test-blocking-io", plus concrete routing rules, a stable match key, and a specific anchor source file. Not 4 because there are no gaps in the runnable guidance — even edge handling (finally-path cleanup bounded with asyncio.wait_for) is spelled out.

Workflow Clarity

Steps 0–6 are clearly sequenced with explicit validation checkpoints and error-recovery loops: Step 2 requires the finding to vanish and sends you back "before touching any test" if it doesn't, and Step 5 is a mandatory red→green teeth gate with a defined RULE escape route when a real block stays green. Matches the 5 anchor (explicit validation, feedback loops) exactly, including for the batch PR-sizing operations.

Progressive Disclosure

Good structure with clearly signaled, one-level-deep references — "Read references/good-anchor-rules.md before writing any anchor" and "Only read references/sop-skeleton.md when generalizing" is exemplary conditional loading — and both referenced files exist in the bundle. Not 5 because Step 3 directs creating an anchor "from templates/anchor.template.py", a path that does not exist in the provided bundle (references/ has only the two .md files), a navigation dead end.

Specificity

The description enumerates the full workflow in concrete verbs — "Runs a deterministic scan (changed-lines or full-repo), routes each candidate, drafts/extends an anchor, and proves it fails when the blocking IO regresses" — which comprehensively covers every phase of the SOP (scope, judge, anchor, teeth). Not the 4 anchor because there is no coverage gap: what the skill does is stated end-to-end, not just as a list of several actions.

Completeness

Explicitly answers both questions: what ("Ensure async-path backend code ... is protected by a teeth-verified runtime anchor in tests/blocking_io/" plus the closing action sentence) and when (a literal "Use when" clause with three distinct concrete triggers: changing backend Python in named dirs, running a triage round, or a reviewer/CI request). Clearly the 5 anchor with concrete trigger phrases.

Trigger Term Quality

Good natural-term coverage for the domain: "block the asyncio event loop", "blocking-IO", "triage round", "reviewer/CI asks for blocking-IO coverage", plus concrete path triggers (app/, packages/harness/deerflow/, scripts/). Not 5 because a few natural synonyms a contributor would actually say are missing (e.g. "sync call", "offload", "event loop blocking"), and there are no file/extension-style anchors.

Distinctiveness Conflict Risk

A narrow, well-defined niche (blocking-IO guarding in one backend's tests/blocking_io/) with distinct, specific triggers; it would not plausibly fire for an unrelated skill. Not 4 because there is no meaningful overlap risk — the domain, paths, and trigger scenarios are all unique to this skill.