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javascript-pro

Writes, debugs, and refactors JavaScript code using modern ES2023+ features, async/await patterns, ESM module systems, and Node.js APIs. Use when building vanilla JavaScript applications, implementing Promise-based async flows, optimising browser or Node.js performance, working with Web Workers or Fetch API, or reviewing .js/.mjs/.cjs files for correctness and best practices.

76

Quality

95%

Does it follow best practices?

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SKILL.md
Quality
Evals
Security

Quality

Content

92%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.

The body is a tight, actionable overview: an ordered workflow with explicit validate-and-retry loops, concrete MUST/MUST-NOT constraints, executable correct/incorrect code examples, and a properly structured reference table pointing to real bundle files. Its only flaw is a couple of example blocks that re-teach basics Claude already knows.

DimensionReasoningScore

Conciseness

The body is lean with no prose padding — constraint lists, a workflow, and code examples — but two of the four pattern blocks ("Avoid var / Prefer const" and basic optional chaining) teach concepts Claude already knows, which fits "minor instances of over-explanation that could be trimmed" rather than the every-token-earns-its-place anchor at 5.

4 / 5

Actionability

Guidance is fully executable: copy-paste-ready code examples showing correct vs. incorrect patterns, concrete commands ("eslint --fix", Jest with "85%+ coverage", "--inspect"/DevTools for leak checks), and specific output deliverables — matching the anchor for executable code covering the common cases.

5 / 5

Workflow Clarity

The five-step Core Workflow is clearly sequenced with explicit validation checkpoints and feedback loops: "if linter fails, fix all reported issues and re-run before proceeding", "if leaks are found, resolve them before continuing", and "if coverage falls short, add missing cases and re-run" — matching the anchor requiring explicit validation steps with error-recovery loops.

5 / 5

Progressive Disclosure

The body is a concise overview with a well-signaled Reference Guide table giving topic, real one-level-deep reference paths (all five files verified to exist), and explicit "Load When" conditions — matching the anchor for clear overview with well-signaled shallow references and easy navigation.

5 / 5

Total

19

/

20

Passed

Description

96%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.

A strong description with explicit what/when structure, comprehensive natural trigger terms including file extensions, and concrete named capabilities. The only weakness is mild overlap with generic code-review and full-stack skills in the reviewing/refactoring triggers.

DimensionReasoningScore

Specificity

The description lists multiple concrete actions — "Writes, debugs, and refactors JavaScript code" — and enumerates the specific technology areas covered ("modern ES2023+ features, async/await patterns, ESM module systems, and Node.js APIs"), matching the comprehensive multi-action anchor rather than the minor-gaps anchor at 4.

5 / 5

Completeness

It explicitly answers both questions: a clear "what" ("Writes, debugs, and refactors JavaScript code using...") followed by an explicit "Use when..." clause with concrete trigger conditions (building vanilla JS apps, implementing Promise flows, optimising performance, working with Web Workers/Fetch, reviewing .js/.mjs/.cjs files).

5 / 5

Trigger Term Quality

Natural user phrases are comprehensively covered with synonyms and file extensions: "JavaScript", "vanilla JavaScript", "async/await", "Promise-based", "Node.js", "Web Workers", "Fetch API", and ".js/.mjs/.cjs files" — matching the anchor requiring synonyms plus extensions.

5 / 5

Distinctiveness Conflict Risk

The niche is mostly distinct — "vanilla JavaScript" and the .js/.mjs/.cjs extensions separate it from framework-specific skills — but "reviewing... for correctness and best practices" and general refactoring overlap with generic code-review/refactoring skills (e.g., the referenced fullstack-guardian), so it fits the "minor overlap risk with closely related skills" anchor rather than minimal conflict risk.

4 / 5

Total

19

/

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

Jeffallan/claude-skills

Path

skills/javascript-pro/SKILL.md

Reviewed

Table of Contents

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