Conciseness

The body is ~30 lines with no padding and no explanation of concepts Claude already knows; every section (Quick Reference, Check, Fix, Explain, Code Review) is a terse directive. The single intro sentence on caching benefits is brief framing, not verbose explanation — matching 'lean and efficient; every token earns its place'.

Actionability

The Quick Reference bullets give concrete policy values ('immutable caching for hashed assets (1 year max-age)', 'short cache + revalidation for HTML'), but the Check and Fix sections are high-level directives ('Verify that proper cache headers are set', 'Configure appropriate Cache-Control and ETag headers') with no commands, code, or method for how to check or apply them — the executable detail lives entirely in references/rule.md. This fits 'some concrete guidance but incomplete; missing key details' rather than 4's 'mostly executable guidance with concrete code or commands'.

Workflow Clarity

The Check → Fix → Explain sequence gives a clear, ordered workflow for a simple non-destructive skill, and the Quick Reference caps it with concrete policies. It falls short of 5 because the Check step provides no verification method or checkpoint (e.g., inspect response headers in DevTools Network tab) and the appended 'Code Review' section reads as a second, separate use case rather than an integrated step — matching 'clear sequence with most checkpoints present; minor validation gaps'.

Progressive Disclosure

SKILL.md is a concise overview (quick-reference policies plus section skeleton) and defers all implementation detail to a single, clearly signaled, one-level-deep reference: 'For full implementation details, code examples, and framework-specific guidance, see references/rule.md' — and references/rule.md exists (230 lines) containing exactly that (Next.js header config, strategy tables, directive reference). This matches 'clear overview with well-signaled one-level-deep references; content appropriately split'.

Specificity

The description names the domain ("auditing slow page loads, heavy assets, or rendering delays related to Enable browser caching") and one concrete action ("Verify the actual bottleneck in DevTools, Lighthouse, or field data"), but does not list the several distinct actions the skill covers (checking headers, configuring Cache-Control/ETag, code review) — matching 'names domain and 1-2 concrete actions'. It falls short of 4 because no additional specific actions are enumerated, and above 2 because the verification action is concrete with named tools.

Completeness

The 'when' is explicit and strong ("Use when auditing slow page loads...") and a 'what' is present ("Verify the actual bottleneck... before recommending changes"), but the core what — enabling/configuring browser caching headers — is only implicit in the fragment "related to Enable browser caching". This fits 'has both what and when; when could be more explicit or specific' inverted (what could be more explicit), not 5 where both are concretely and explicitly stated.

Trigger Term Quality

Natural phrases users would say are present: "slow page loads", "heavy assets", "rendering delays", "browser caching", plus tool names "DevTools, Lighthouse". A few common natural terms are missing (e.g., "page speed", "load time", "cache headers", "Cache-Control"), fitting 'good keyword coverage; a few natural terms missing' rather than the comprehensive synonym/extension coverage of 5.

Distinctiveness Conflict Risk

The scope is narrowed to browser caching ("related to Enable browser caching"), with distinct tool triggers (DevTools, Lighthouse, field data), giving a mostly distinct niche. Minor overlap risk remains with sibling performance skills that also trigger on "slow page loads" or "heavy assets" (e.g., image optimization, bundle size), so it does not reach the minimal-conflict clarity of 5 but is well above the broad overlap of 3.