code-formatter
Execute automatically formats and validates code files using Prettier and other formatting tools. Use when users mention "format my code", "fix formatting", "apply code style", "check formatting", "make code consistent", or "clean up code formatting". Handles JavaScript, TypeScript, JSON, CSS, Markdown, and many other file types. Trigger with relevant phrases based on skill purpose.
88
87%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Passed
No known issues
Quality
Discovery
89%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is a solid description with strong trigger terms and clear completeness. The explicit 'Use when...' clause with natural user phrases is well done, and the tool/file type specificity helps distinguish it. The main weakness is that the capability description could be more detailed with additional concrete actions beyond 'formats and validates'. The trailing sentence 'Trigger with relevant phrases based on skill purpose' is vague filler that adds no value.
Suggestions
Remove the vague trailing sentence 'Trigger with relevant phrases based on skill purpose' as it adds no information and is filler.
Expand the specific actions beyond 'formats and validates' — e.g., 'auto-fixes indentation, enforces consistent quotes and semicolons, validates config files, formats on save'.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Names the domain (code formatting) and mentions specific tools (Prettier) and file types, but the actual actions are somewhat limited — 'formats and validates' are the only concrete actions listed. It doesn't enumerate distinct capabilities like 'check for errors, auto-fix style issues, enforce config rules'. | 2 / 3 |
Completeness | Clearly answers both 'what does this do' (formats and validates code files using Prettier) and 'when should Claude use it' with an explicit 'Use when...' clause listing multiple trigger phrases. | 3 / 3 |
Trigger Term Quality | Includes a strong set of natural trigger phrases users would actually say: 'format my code', 'fix formatting', 'apply code style', 'check formatting', 'make code consistent', 'clean up code formatting'. Also mentions specific file types like JavaScript, TypeScript, JSON, CSS, Markdown. | 3 / 3 |
Distinctiveness Conflict Risk | The focus on code formatting with Prettier is a clear niche. The trigger terms are specific to formatting/style concerns and unlikely to conflict with general coding, linting, or other development skills. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
85%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a well-structured skill with strong actionability and clear workflow sequencing. The progressive disclosure is well-handled with appropriate references to supporting files. The main area for improvement is conciseness—some sections (prerequisites, output description) could be tightened to respect token budget, and the error table partially overlaps with the referenced errors.md file.
Suggestions
Trim the prerequisites section—Claude knows what file extensions are and doesn't need them listed; focus only on non-obvious requirements like Prettier installation.
Consider removing or significantly condensing the error handling table since errors.md is already referenced, or remove the errors.md reference and keep the table as the single source.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The content is mostly efficient but includes some unnecessary verbosity. The prerequisites section explains things Claude would know (what file extensions are supported), and the error handling table, while useful, partially duplicates what would be in the referenced errors.md. The output section describes what to produce in a somewhat verbose way. | 2 / 3 |
Actionability | The instructions provide specific, executable commands at each step (e.g., `npx prettier --check "**/*.{js,jsx,ts,tsx,json,css,md}" --ignore-path .prettierignore`). The error handling table gives concrete solutions with actual commands. Examples include specific trigger phrases and concrete processes. | 3 / 3 |
Workflow Clarity | The 7-step workflow is clearly sequenced: check availability → detect config → check formatting → apply formatting → set up ignore file → optional hooks → final validation. Step 7 serves as an explicit validation checkpoint confirming compliance after changes, and step 3 provides a check-before-write pattern. | 3 / 3 |
Progressive Disclosure | The skill provides a clear overview with well-signaled one-level-deep references to `references/implementation.md` for detailed configuration examples and `references/errors.md` for extended error scenarios. The main content stays at an appropriate summary level while pointing to deeper resources. | 3 / 3 |
Total | 11 / 12 Passed |
Validation
81%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 9 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
allowed_tools_field | 'allowed-tools' contains unusual tool name(s) | Warning |
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 9 / 11 Passed | |
- Commit
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