Conciseness

The body is a lean, checklist-style rule set with no explanations of what accessibility is or why it matters beyond one short sentence per rule — it assumes Claude's competence throughout. Minor trimmable redundancy exists: the priority table's "impact" column duplicates the priority labels already shown in each section heading ("### 1. accessible names (critical)"), keeping it just below the every-token-earns-its-place 5 anchor.

Actionability

Rules are concrete directives with exact attribute names ("aria-describedby", "aria-invalid", "do not use tabindex greater than 0") and the "common fixes" section provides copy-paste-ready before/after HTML for three common cases. A few rules remain directional rather than executable — e.g., "if a role is used, required aria attributes must be present" never says which attributes, and there is no example for focus trapping in dialogs — so it sits below fully-executable 5.

Workflow Clarity

The invocation modes are explicit (apply constraints conversation-wide, or per-file review with a defined report format: quote snippet, why it matters, concrete fix), and "review guidance" sequences the work (fix critical categories first, prefer native elements, use established primitives for complex widgets). This is a review skill, not a destructive/batch operation, so no validation cap applies; the gap keeping it below 5 is the absence of any post-fix verification step (e.g., re-checking the fixed snippet or confirming no regression).

Progressive Disclosure

No bundle files exist (references/, scripts/, assets/ are all absent) and the body references no external paths, so scoring is against the single-file structure. Organization is good: numbered sections, a priority index table, a quick-reference hierarchy, and a common-fixes code block. The 5 anchor's well-signaled one-level-deep reference structure does not apply and the skill exceeds the under-50-lines simple-skill exception at ~137 lines, so this lands at 4 — well-structured, with the rule catalog being the kind of content that could optionally split into a reference file.

Specificity

The description lists several specific capabilities — "Audit and fix HTML accessibility issues including ARIA labels, keyboard navigation, focus management, color contrast, and form errors" — with concrete objects for each. It stops short of the 5 anchor's multiple distinct action verbs (only "audit" and "fix") and omits a few areas like alt text and media, which is a minor gap in coverage.

Completeness

It clearly answers both questions: what it does ("Audit and fix HTML accessibility issues including...") and when to use it ("Use when adding interactive controls, forms, dialogs, or reviewing WCAG compliance"). The 'when' clause contains explicit, concrete trigger phrases, matching the 5 anchor; the 4 anchor's caveat about a less-explicit 'when' does not apply.

Trigger Term Quality

Good keyword coverage: "ARIA labels", "keyboard navigation", "focus management", "color contrast", "form errors", "WCAG compliance", "interactive controls", "forms", "dialogs" are all natural phrases a user would say. A few common synonyms are missing (e.g., "a11y", "screen reader", "alt text"), keeping it below the comprehensive 5 anchor.

Distinctiveness Conflict Risk

It occupies a clear niche (HTML accessibility) with distinct trigger terms (ARIA, WCAG, keyboard navigation, focus management) that are unlikely to fire for unrelated skills. Minor overlap with a generic frontend/forms skill exists but the WCAG/ARIA vocabulary is unmistakably accessibility-specific.