Conciseness

The body is mostly lean with useful section structure, but the Code Review section ("Review authenticated forms, checkout flows, editors, and long-running tasks") substantially duplicates the Check section's scope, and "related to Prevent data loss from session timeouts" is filler. Minor trimmable redundancy matches the 4 anchor; it is not the 5 anchor's every-token-earns-its-place level.

Actionability

Concrete, specific guidance for an instruction-only skill: "Verify users are told the timeout duration, warned before expiry, can extend the session... and restore the user to the same step" names exact checks and fixes, with implementation examples delegated to references/rule.md. It falls short of the 5 anchor because no inline example of a flaggable anti-pattern (e.g., a silent setTimeout redirect) is shown in the body itself.

Workflow Clarity

The Check → Fix → Explain → Code Review ordering plus the Quick Reference checklist gives a clear sequence for a review skill, and no destructive/batch cap applies. It does not reach the 5 anchor because verification checkpoints are implicit — there are no explicit test steps such as confirming the warning dialog is keyboard-reachable and announced to assistive technology.

Progressive Disclosure

A ~45-line overview with well-organized sections and a single clearly signaled, one-level-deep reference ("For full implementation details, code examples, and framework-specific guidance, see references/rule.md") that exists and contains the code examples. This matches the top anchor: appropriate split, easy navigation, no nesting.

Specificity

The description enumerates five concrete action areas ("warning timing, dialog accessibility, autosave frequency, timeout extension, and post-login state restoration") plus an explicit client/server scope split, giving comprehensive coverage of the skill's niche. This matches the anchor for multiple specific concrete actions with comprehensive coverage; the level-4 anchor (minor gaps) fits worse since no meaningful capability is missing.

Completeness

It explicitly answers both questions: "Use when reviewing authenticated user flows or long forms" gives concrete triggers, and the enumerated check behaviors state exactly what the skill does. This matches the top anchor; the 4 anchor's weaker/less-explicit 'when' does not apply here.

Trigger Term Quality

Natural phrases like "authenticated user flows", "long forms", and "post-login" are present, but the most likely user phrasings — "session timeout", "session expiry", "logged out" — never appear literally. Good keyword coverage with a few natural terms missing matches the 4 anchor; it falls short of the 5 anchor's comprehensive synonym coverage.

Distinctiveness Conflict Risk

Phrases like "timeout extension", "autosave frequency", and "post-login state restoration" carve a distinct WCAG timing-recovery niche, so it is unlikely to trigger for unrelated skills. Matches the clear-niche anchor; the 4 anchor's minor overlap risk is not evidenced.