Conciseness

The body is short, well-sectioned, and assumes Claude's competence — e.g. "Duplicate IDs on active elements can cause browsers and assistive technologies to skip items, misdirect focus, or fail to trigger the correct action" adds rule-specific consequences, not general HTML knowledge. It is not 5 because the three "Quick Reference" bullets ("Ensure all focusable elements... have unique id values", "Avoid duplicate IDs...", "Prevent screen reader confusion...") largely restate the Check/Fix/Explain sections that follow, which is a minor but trimmable redundancy.

Actionability

The Check section gives one concrete instruction — "Search for duplicate id attributes on focusable or active HTML elements" — and Fix gives a clear remedy ("Assign a unique id to each active element"), but no executable method is provided in the body: no search command, selector (e.g. document.querySelectorAll('[id]')), lint/axe invocation, or worked example. This matches the anchor 'some concrete guidance but incomplete; missing key details', and exceeds score 2 because the guidance is specific about what to look for and how to fix it.

Workflow Clarity

The Check → Fix → Explain → Code Review sections give a clear, unambiguous sequence for a simple, non-destructive skill, and the Code Review section includes verification guidance ("note how to verify the fix with browser accessibility tooling or assistive tech"). It is not 5 because verification is mentioned only as something to "note" rather than an explicit checkpoint (e.g. re-run an axe/lint audit and confirm no duplicate-id violations remain), so a validation step is implicit rather than built in.

Progressive Disclosure

The body is a concise overview under 50 lines with a single clearly signaled, one-level-deep pointer — "For full implementation details, code examples, and framework-specific guidance, see `references/rule.md`" — and that file exists and contains exactly the promised implementation details, code examples, and framework guidance. This matches the anchor for a clear overview with well-signaled one-level-deep references and easy navigation.

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 none of the actions state the skill's core operation (detecting duplicate IDs or assigning unique IDs); the actions are generic accessibility-review verbs rather than this rule's specifics.

Completeness

Both parts are present: an explicit "Use when reviewing rendered HTML, interactive components, or design-system patterns..." trigger plus check/inspect actions as the 'what'. It does not reach 5 because the 'what' never states what the skill actually does about the problem (find duplicate IDs / assign unique IDs), leaving the core capability implicit.

Trigger Term Quality

Natural trigger terms are present — "rendered HTML", "interactive components", "design-system patterns", "keyboard", "focus", "screen-reader" — giving good keyword coverage. It is not 5 because common user phrasings like "duplicate IDs", "accessibility audit/review", or "a11y" are absent, and the phrase "related to Use unique IDs for active elements" awkwardly embeds the rule title rather than a natural keyword.

Distinctiveness Conflict Risk

The description is scoped to a clear niche — unique IDs on active elements within HTML/accessibility review — so it is mostly distinct with minor overlap risk against sibling accessibility-rule skills that share the same "rendered HTML, interactive components" trigger phrasing. It is not 5 because that shared generic trigger clause would fire for many related accessibility skills in the same family.