Conciseness

The body is efficient: the five-line ratchet explanation is load-bearing domain context, the gate script is compact, and the anti-patterns table is dense. Minor trimmable padding remains — the sibling-gate list appears twice (Overview and References) and Step 2's 'never auto-update from CI' guidance is restated in the anti-patterns table — so it fits 'efficient; minor instances that could be trimmed' rather than the every-token-earns-its-place level 5.

Actionability

Step 3 ships a fully executable, copy-paste-ready Python gate (reads axe-results.json and a11y-baseline.json, computes blockers/warnings/fixed, exits non-zero on no-go), plus concrete JSON schemas for the unified record and baseline and an explicit severity-tier table. The common case (axe-core) is covered inline with the other four scanners delegated via clearly-signaled real reference — matching the level-5 anchor.

Workflow Clarity

Steps 1–5 are clearly sequenced, and the gate decision itself is an explicit validation checkpoint with severity-tier behavior. Feedback loops for error recovery are present in Step 5 (gate fails → fix or debate baseline; fix → remove fingerprint in the same PR; quarterly review), matching the level-5 anchor of explicit validation steps and recovery loops. There are no destructive auto-updates — baseline mutation is deliberately manual and called out.

Progressive Disclosure

SKILL.md is an overview plus the core runnable gate, with per-scanner field mappings and the full PR artifact template correctly pushed to references/gate-implementation.md — a real, substantive file referenced three times with purpose stated each time, exactly one level deep. The split (core logic inline, bulk detail external) matches the level-5 anchor; level 4 would require organization gaps that are not present.

Specificity

Quotes multiple concrete actions — 'Builds a CI ratchet that fails only on new WCAG violations a PR introduces', 'with pre-existing ones baselined per rule and page' — and names all five supported scanners (axe-core, pa11y, Lighthouse, WAVE, IBM Equal Access). Coverage of the skill's capability is comprehensive, matching the level-5 anchor; level 4 would require minor gaps in coverage, which are absent.

Completeness

Explicitly answers both questions: 'Use when a project has accessibility debt and a zero-violations gate would block every PR' (when, with concrete trigger conditions) and 'Builds a CI ratchet that fails only on new WCAG violations...' (what). This matches the level-5 anchor of clear what AND when with concrete trigger phrases; level 4 would require a weaker or less explicit 'when' clause.

Trigger Term Quality

Strong natural keywords: 'accessibility debt', 'zero-violations gate', 'WCAG violations', 'PR', plus the five scanner names users would actually say. A few common variations are missing — notably the 'a11y' shorthand and phrasings like 'accessibility regression' — so it fits 'good keyword coverage; a few natural terms missing' rather than the comprehensive synonym coverage of level 5.

Distinctiveness Conflict Risk

A clear niche — CI accessibility gating via a baseline ratchet — with distinct triggers (WCAG violations, the five scanner names, per-rule/per-page baselining). It is unlikely to fire for unrelated skills; the only adjacent territory is sibling gate skills, which the description's scanner-specific framing keeps minimal, matching the level-5 anchor.