Conciseness

The 53% abandonment statistic is stated twice ('53% of mobile users abandon sites that take longer than 3 seconds' in the intro and '53% of mobile users abandon sites taking over 3 seconds' in Quick Reference), and the bounce-rate theme recurs across the intro, Quick Reference, and the 'Explain' section. Mostly efficient but with noticeable duplication that could be tightened — anchor 3, not 4, since the redundancy goes beyond minor trimming.

Actionability

'Measure the page load time and verify it's under 3 seconds' and 'Optimize page load time through lazy loading, CDN usage, caching strategies' give high-level direction with no tool, command, or code in the body. Concrete specifics do appear ('Core Web Vitals: LCP, FID/INP, CLS', 'Test on throttled 3G') and the pointer to references/rule.md leads to complete executable examples, but key details — which tool, how to measure — are missing. Anchor 3, not 4, because the core Check/Fix actions lack executable guidance in the body.

Workflow Clarity

The Check → Fix → Explain → Code Review sequence is clearly sectioned and logically ordered, and the check step validates ('verify it's under 3 seconds on a standard connection'). However, there is no re-verification after applying fixes — no measure → optimize → re-measure feedback loop — so checkpoints are incomplete. Anchor 3, not 4: the post-fix checkpoint is absent entirely, not just minor.

Progressive Disclosure

The body is a ~30-line well-sectioned overview, with implementation details, code examples, and framework guidance correctly split into references/rule.md — one level deep, clearly signaled ('For full implementation details, code examples, and framework-specific guidance, see references/rule.md'), and that file exists and does not nest further references. This matches the anchor 5 pattern of a clear overview with well-signaled one-level-deep references.

Specificity

The description names the domain ('auditing slow page loads, heavy assets, or rendering delays') and one concrete action ('Verify the actual bottleneck in DevTools, Lighthouse, or field data'), but never states what the skill does beyond auditing/verifying — the fix, explain, and code-review capabilities from the body are absent. It matches anchor 3 (domain plus 1-2 concrete actions) rather than 4, which requires several specific actions listed.

Completeness

It has an explicit 'when' ('Use when auditing slow page loads, heavy assets, or rendering delays') and a partial 'what' ('Verify the actual bottleneck... before recommending changes'), but the what is folded into the when-clause and the phrase 'related to Keep page load time under 3 seconds' is a garbled goal statement inserted mid-sentence. Both are present with the what muddy, matching anchor 4 rather than the fully explicit anchor 5.

Trigger Term Quality

Phrases like 'slow page loads', 'heavy assets', 'rendering delays', and 'DevTools, Lighthouse' are natural terms users would say when needing this skill. It falls short of anchor 5 because common synonyms such as 'site speed', 'page performance', 'Core Web Vitals', or 'LCP' are missing.

Distinctiveness Conflict Risk

'Slow page loads' and 'page load time' are on-niche, but 'heavy assets' and 'rendering delays' are generic performance triggers that would equally fire image-optimization or rendering-performance skills. It is somewhat specific yet still overlaps with closely related performance skills, matching anchor 3 rather than 4.