The body is lean: a one-line problem statement plus short Quick Reference bullets and terse Check/Fix/Explain/Code Review imperatives, with details deferred to references/rule.md. It assumes Claude's competence and does not pad with concepts Claude already knows, matching the 'every token earns its place' anchor.

The Check/Fix/Explain sections give clear direction ('Find hard-coded color values... that should be replaced', 'Extract repeated and meaningful values into CSS custom properties on :root and replace all usages with var()'), but there is no executable code or copy-paste-ready example in the body — those live only in the reference — so it stops at 'some concrete guidance but incomplete'.

The sections imply a sequence (Check → Fix → Explain → Code Review) and the description mandates verifying rendered layout across breakpoints before proposing a fix, but the body itself lists steps without an explicit validation checkpoint or feedback loop tying the verify-before-fix instruction into the workflow, so checkpoints are only implicit.

The body is a concise overview with a single, clearly signaled one-level-deep reference ('For full implementation details, code examples, and framework-specific guidance, see references/rule.md'), and the referenced file exists and holds the detailed material; content is appropriately split and easy to navigate, matching the 3-anchor example.

It names a domain (stylesheets, component styles, responsive behavior) and a concrete action ('Check the rendered layout across breakpoints and interaction states before proposing a fix'), but the capability list is narrow and the awkward embedded rule title ('related to Use CSS custom properties for design tokens') is not a described action, so it does not reach the 'multiple specific concrete actions' level of 3.

It explicitly answers both 'what' (review stylesheets/component styles/responsive behavior, check rendered layout across breakpoints and interaction states before proposing a fix) and 'when' via an explicit 'Use when...' clause, matching the 3-anchor example with an explicit trigger.

It opens with a natural trigger ('Use when reviewing stylesheets, component styles, and responsive behavior') a user might say, and mentions 'breakpoints' and 'interaction states', but it is missing common natural variations a user would actually say (e.g. 'CSS variables', 'design tokens', 'theming', 'dark mode'), and the literal rule-title phrasing is not a natural keyword.

It is scoped to CSS custom properties / design tokens, which gives it a niche, but the leading framing ('reviewing stylesheets, component styles, and responsive behavior') is broad enough to overlap with other general CSS/review skills, so it could still trigger for similar skills rather than being a clearly distinct niche.