tessl-labs/web-performance
Web performance patterns — lazy loading, bundle optimization, query optimization, compression, and resource management
81
77%
Does it follow best practices?
Impact
97%
3.23xAverage score across 3 eval scenarios
Passed
No known issues
Quality
Discovery
60%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 excels at listing specific, concrete optimization techniques but falls short on trigger guidance. It lacks a clear 'Use when...' clause and natural user language that would help Claude select this skill appropriately. The scope of 'production apps' is also somewhat broad and could benefit from more precise boundaries.
Suggestions
Add an explicit 'Use when...' clause with natural trigger phrases like 'Use when optimizing web app performance, addressing slow page loads, reducing bundle size, or improving Core Web Vitals'
Include common user language variations such as 'slow website', 'page speed', 'loading time', 'performance optimization' alongside the technical terms
Narrow the scope by specifying the type of applications (e.g., 'web applications', 'React/Node apps') to reduce potential conflicts with other optimization-related skills
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: lazy loading, code splitting, image optimization, database query optimization, response compression, pagination, and resource cleanup. | 3 / 3 |
Completeness | Clearly answers 'what' with specific optimization patterns, but the 'when' is weak - 'in production apps' and 'apply proactively' is vague and lacks explicit trigger guidance like 'Use when...' clause. | 2 / 3 |
Trigger Term Quality | Contains technical terms like 'lazy loading', 'code splitting', 'pagination' that developers would use, but lacks common user phrases like 'make my app faster', 'speed up', 'performance issues', or 'slow loading'. | 2 / 3 |
Distinctiveness Conflict Risk | Focuses on web performance which is somewhat specific, but 'production apps' is broad and could overlap with general web development, deployment, or backend optimization skills. | 2 / 3 |
Total | 9 / 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 strong, highly actionable skill that provides comprehensive web performance patterns with excellent executable examples. The WRONG/RIGHT code comparisons are particularly effective for teaching. The main weakness is some verbosity in explanations—Claude doesn't need to be told why unbounded arrays are problematic or what N+1 queries are; it just needs the patterns to apply.
Suggestions
Remove explanatory text that describes problems Claude already understands (e.g., 'will crash or timeout on large tables', 'Never query inside a loop') and keep only the pattern implementations
Consider condensing the ORM examples into a single reference table rather than showing each ORM separately with similar patterns
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is comprehensive but includes some unnecessary explanation (e.g., explaining why unbounded arrays are bad, what N+1 queries are). While mostly efficient, several sections could be tightened—Claude already understands these concepts and needs only the patterns. | 2 / 3 |
Actionability | Excellent actionability with fully executable code examples across multiple languages/frameworks (TypeScript, Python, SQL, HTML). Every pattern includes copy-paste ready WRONG vs RIGHT comparisons with complete, runnable code. | 3 / 3 |
Workflow Clarity | For a patterns/checklist skill, workflow clarity is excellent. The final checklist provides clear validation checkpoints, and each section has explicit 'WRONG' vs 'RIGHT' patterns that serve as verification criteria. The structure is logical and sequential. | 3 / 3 |
Progressive Disclosure | Well-organized with clear sections, a summary checklist at the end, and appropriate references to external resources (web.dev, React docs, MDN) and related verifiers. Content is appropriately structured within a single file given its nature as a comprehensive patterns reference. | 3 / 3 |
Total | 11 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 10 / 11 Passed | |
Reviewed
Table of Contents