Conciseness

The ~30-line body is efficient: a quick-reference bullet list, terse Check/Fix/Explain/Code Review sections, and a pointer to references. Minor trims exist — the 500KB/1500KB thresholds are repeated between Quick Reference and Check, and the intro line 'Page weight directly correlates with load time—a 1.5MB page takes 3-5 seconds on 4G mobile' explains knowledge Claude already has. Fits anchor 4 (efficient, minor over-explanation) rather than 5.

Actionability

Some concrete guidance exists — specific thresholds ('under 1500KB (ideally under 500KB)'), prioritized contributors ('Images typically account for 50-70%'), and named fix levers ('image optimization, code minification, and removing unnecessary resources') — but the Check section gives no measurement method or command, and Fix is high-level direction rather than executable steps. Anchor 3 ('some concrete guidance but incomplete') fits; the specific numbers and the pointer to executable code in references/rule.md keep it above anchor 2's bare hints.

Workflow Clarity

A recognizable sequence is present (Quick Reference → Check → Fix → Explain → Code Review), but there is no validation checkpoint — nothing instructs re-measuring page weight after optimization to confirm the reduction, and the Code Review section's 'describe the measurement method used to confirm the issue' is implied rather than a distinct step. Anchor 3 ('steps listed but validation gaps, checkpoints missing or implicit') fits better than anchor 4.

Progressive Disclosure

The body is a concise overview and all implementation detail is correctly deferred to a single, clearly signaled, one-level-deep reference — 'For full implementation details, code examples, and framework-specific guidance, see references/rule.md' — which was verified to exist and contain the code examples and benchmark tables. Content is appropriately split and navigation is easy, matching the anchor 5 example.

Specificity

Lists several concrete actions with named tools — 'auditing slow page loads, heavy assets, or rendering delays' and 'Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes' — but coverage gaps remain (the optimization/fix guidance the skill actually provides is never mentioned). It exceeds anchor 3 (more than 1-2 actions, tools named) but falls short of anchor 5's comprehensive action list.

Completeness

Explicit 'Use when auditing slow page loads, heavy assets, or rendering delays' trigger clause is present (avoiding the cap at 3), and the 'what' is stated concretely ('Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes'). Not a 5 because the awkward embedded phrase 'related to Keep page weight under 1500KB' muddies both clauses, and the fix/optimization capability is unstated.

Trigger Term Quality

Good natural keyword coverage: 'slow page loads', 'heavy assets', 'rendering delays', 'page weight', 'DevTools', 'Lighthouse' — phrases users would plausibly say. Falls between anchor 3 and 5 because common synonyms like 'page size', 'bundle size', or generic 'site is slow' phrasing are missing.

Distinctiveness Conflict Risk

The page-weight threshold and 'heavy assets' focus give it a niche, but the broad complaint triggers 'slow page loads' and 'rendering delays' would equally fire for many sibling performance-audit skills (image optimization, lazy loading, Lighthouse auditing). Fits anchor 3 — somewhat specific but real overlap risk with closely related skills — rather than anchor 4's 'minor overlap risk only'.