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starlight-custom-component

Create and override Astro Starlight UI components. Use when replacing or extending built-in Starlight components (header, footer, sidebar, page title, etc.), adding custom UI alongside existing components, accessing page route data inside a component, or applying overrides conditionally on specific pages.

Quality

94%

Does it follow best practices?

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Passed

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SKILL.md
Quality
Evals
Security

Quality

Content

86%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A strong, highly actionable skill body: complete executable examples, a clear philosophy section, and exemplary progressive disclosure with a verified one-level reference file. The only real costs are duplicated guidance between the 'When (Not) to Use' sections and the anti-patterns, and the absence of an explicit post-registration verification step.

Suggestions

Merge the 'When Not to Use' bullets into the corresponding anti-patterns (or vice versa) so the CSS-belongs-in-starlight-theme and content-belongs-in-starlight-base guidance appears once instead of twice.

Add a brief Step 4 to the override workflow telling the reader to run the dev server and visually confirm the override applies, turning each anti-pattern's stated consequence into a checkable validation point.

Show the named-slot transfer snippet for layout components only once (in the wrapping section or the anti-pattern) and point to references/overrides-reference.md for the other, since the same code currently appears three times.

DimensionReasoningScore

Conciseness

Prose is lean with no over-explanation of concepts Claude already knows, but there is noticeable duplication: 'When to Use'/'When Not to Use' restate the description and reappear nearly verbatim as anti-patterns ('NEVER override a component when CSS alone is enough', 'NEVER use this skill to add documentation pages'), and the named-slot transfer snippet appears twice in the body plus once in the reference file.

4 / 5

Actionability

All guidance is concrete and copy-paste ready: a complete component file, the exact `astro.config.mjs` registration snippet, the wrapping pattern with the default-import path, `Astro.locals.starlightRoute` data access, and named-slot transfer code. The common cases (replace, wrap, conditional rendering) are each covered by executable examples.

5 / 5

Workflow Clarity

The 'Step-by-Step' section gives a clear three-step sequence (identify slot → create component → register in config), and each anti-pattern pairs a WHY with an explicit Consequence that functions as error recognition. However, no explicit verification step (e.g., run the dev server and confirm the override applies) is given, leaving a minor validation gap.

4 / 5

Progressive Disclosure

The body is a well-organized overview that keeps bulk tabular detail (full component list, starlightRoute property table) in `references/overrides-reference.md` — a real file referenced twice with clear signaling ('See overrides-reference.md for the full property table'). The closing References table with topic and 'When to Use' columns makes navigation easy, and references are exactly one level deep.

5 / 5

Total

18

/

20

Passed

Description

100%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description is a model example: it pairs a concise statement of capability with an explicit, multi-clause 'Use when...' trigger list naming concrete components and scenarios. Every dimension lands on the top anchor.

DimensionReasoningScore

Specificity

The description lists multiple concrete actions — 'Create and override Astro Starlight UI components', 'replacing or extending built-in Starlight components (header, footer, sidebar, page title, etc.)', 'adding custom UI alongside existing components', 'accessing page route data inside a component', 'applying overrides conditionally on specific pages' — giving comprehensive coverage of the skill's capabilities with no gaps.

5 / 5

Completeness

It explicitly answers both questions: the first sentence states what the skill does ('Create and override Astro Starlight UI components') and a full 'Use when...' clause gives four concrete trigger scenarios (replacing/extending, adding UI, accessing route data, conditional overrides).

5 / 5

Trigger Term Quality

Natural trigger terms users would say are comprehensively covered: 'Starlight', 'override', 'extend', 'custom UI', 'header, footer, sidebar, page title', 'route data'. Synonyms ('replacing or extending', 'adding custom UI alongside') and concrete component names match how a user would phrase the request.

5 / 5

Distinctiveness Conflict Risk

The niche is narrow and clearly bounded — Astro Starlight component overrides — with trigger terms ('Starlight components', 'overrides', named slots like header/footer/sidebar) that would not fire for sibling skills such as theming or content authoring.

5 / 5

Total

20

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

pantheon-org/tekhne

Path

skills/documentation/astro-starlight/skills/starlight-custom-component/SKILL.md

Reviewed

Table of Contents

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