Conciseness

The body is dominated by lean token tables and copy-paste code examples with almost no explanation of concepts Claude already knows. Minor trimmable padding remains: the vacuous closer 'This skill is applicable to execute the workflow or actions described in the overview', and the Anti-Patterns section repeats WRONG/CORRECT pairs already shown in the token sections. This is 'Efficient; minor instances of over-explanation that could be trimmed', not level 5 where every token earns its place.

Actionability

Concrete TSX examples with correct/wrong pairs cover tokens, components, and layout patterns, and the Component Props Pattern shows a complete typed component. Minor gaps: the import path ('components/core') appears only in an anti-pattern snippet, and Icon, Avatar, Heading, and Screen are used in examples without any prop documentation. Fits 'Mostly executable guidance; concrete code or commands with minor gaps' rather than the fully copy-paste-ready level 5.

Workflow Clarity

This is a reference-style skill, so no multi-step sequence is needed; the core directive ('NEVER hard-code values. Always use design tokens.') is unambiguous, stated up front, and reinforced by the anti-pattern correct/wrong pairs, and no destructive or batch operations require validation checkpoints. It is not a simple single-action skill — it spans tokens, several components, and layout patterns — so the simple-skill 5 exception does not apply, and component discovery beyond the listed examples is left implicit. Level 4 fits: clear, unambiguous guidance with minor gaps.

Progressive Disclosure

No bundle files exist (references/, scripts/, assets/ are all absent), so all content lives in a single well-sectioned ~260-line file with a clear header hierarchy (tokens → components → patterns → anti-patterns) that is easy to navigate. There are no buried or nested references to penalize, but the full token tables and per-component documentation are natural candidates for a one-level-deep reference file if the library grows, keeping this at 'Good structure; minor organization gaps' rather than level 5's clean overview-plus-references split.

Specificity

The description names the domain ("Core component library and design system patterns") but lists no concrete actions — the what-clause is a bare noun phrase, and activities only appear inside the trigger clause. This matches the anchor 'Names the domain but actions are minimal or generic' rather than level 3, which requires 1–2 explicitly named concrete actions.

Completeness

Both parts are present: a what ('Core component library and design system patterns') and an explicit when ('Use when building UI, using design tokens, or working with the component library'). The what is weak (a domain label rather than action statement) and the when could be more specific, so it sits at level 4 rather than the fully concrete level 5.

Trigger Term Quality

Trigger terms 'building UI', 'using design tokens', and 'working with the component library' are natural phrases a user might say, but common variations and synonyms ('design system', 'styling', 'theming', 'components') are missing. Fits 'Some relevant keywords but missing common variations or synonyms'; not level 4, which expects only a few natural terms missing.

Distinctiveness Conflict Risk

'Building UI' is broad and would overlap with any general UI or styling skill, though 'design tokens' and 'component library' narrow the niche. It could still be confused with sibling skills like the referenced 'react-ui-patterns', matching 'Somewhat specific but could still overlap with similar skills'.