Conciseness

The body is short and mostly efficient, but the vestibular-disorder rationale appears nearly verbatim in both the intro ("can trigger vertigo, nausea, and disorientation for users with vestibular disorders") and the Explain section, the Fix section restates the Quick Reference bullets, and the Code Review section is generic boilerplate ("Flag exact elements, roles, labels, focus behavior..."). This matches 'mostly efficient but includes some unnecessary explanation or could be tightened' rather than level 4, which requires only minor trimming.

Actionability

The Fix section names the concrete mechanism ("Use scroll-behavior: smooth only within a prefers-reduced-motion media query check", "Ensure focus moves to the anchor target") but includes no code and leaves the media-query direction ambiguous — the correct pattern is '@media (prefers-reduced-motion: no-preference)' while the body's phrasing could be read as wrapping in a 'reduce' query. This lands at 'some concrete guidance but incomplete... missing key details' rather than level 4's mostly executable guidance; the absence of code itself is acceptable for an instruction-only skill, but the ambiguity is not.

Workflow Clarity

For a simple single-purpose review skill the Check/Fix/Explain/Code Review structure is coherent, and the Check step is specific ("Click anchor links... and verify smooth scrolling is disabled when prefers-reduced-motion is set. Confirm anchor navigation works correctly with keyboard and screen readers"). It misses 5 because the body omits how to actually enable prefers-reduced-motion when testing (that checkpoint lives only in references/rule.md), leaving a minor validation gap characteristic of level 4.

Progressive Disclosure

The body is a concise, well-sectioned overview that defers implementation detail to a real, one-level-deep, clearly signaled reference ("For full implementation details, code examples, and framework-specific guidance, see `references/rule.md`"). The referenced file exists (verified: references/rule.md contains the CSS/JS/React examples and verification steps), the split is appropriate, and navigation is easy — matching the top anchor.

Specificity

The description lists several concrete actions — "Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output" — which matches the anchor for several specific actions with minor gaps. It falls short of 5 because the core technical subject (scroll-behavior, prefers-reduced-motion) is never named as an action, only embedded via the awkward rule title "related to Provide instant anchor scroll option".

Completeness

Both parts are explicit: the 'what' is "Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output" and the 'when' is "Use when reviewing rendered HTML, interactive components, or design-system patterns related to...". It misses 5 because the trigger clause leans on the embedded rule title rather than concrete natural trigger phrases, fitting level 4's 'when could be more explicit or specific'.

Trigger Term Quality

Relevant keywords are present ("rendered HTML", "interactive components", "anchor scroll", "keyboard behavior", "screen-reader output"), but the natural phrases a user would actually say for this rule — "smooth scroll", "scroll-behavior", "prefers-reduced-motion", "reduced motion" — are all missing. This matches 'some relevant keywords but missing common variations or synonyms' rather than level 4's 'good keyword coverage'.

Distinctiveness Conflict Risk

The generic scaffolding ("reviewing rendered HTML, interactive components, or design-system patterns... inspect keyboard behavior, focus flow, accessible names, and screen-reader output") is boilerplate that would equally describe many sibling accessibility-review skills; only the embedded rule title distinguishes it. This matches 'somewhat specific but could still overlap with similar skills' rather than level 4's 'mostly distinct'.