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performance-optimization

Profiles, reduces frontend/backend costs: split bundles, optimize assets, apply caching, fix Core Web Vitals regressions. Use when profiling Lighthouse/CI regressions, reducing bundle size, or fixing high CLS/LCP/TTI metrics.

75

Quality

92%

Does it follow best practices?

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SecuritybySnyk

Passed

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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.

A tight, high-quality skill body: lean prose, concrete tooling and thresholds, and a five-step workflow with explicit validation gates and a rollback loop. The only minor gap is the absence of copy-paste-ready command examples for the profiling tools.

DimensionReasoningScore

Conciseness

The body is lean and efficient ("Measure before changing anything", "Ship only at ≥10% improvement or once inside budget") with zero padding and no explanation of concepts Claude already knows; every line adds a constraint, threshold, or procedure step, matching the 5 anchor.

5 / 5

Actionability

Concrete tools, flags, and thresholds are named ("clinic.js or node --inspect", "<Profiler onRender>", "--preset=desktop", "≤200 ms", "300 ms"), but no copy-paste-ready command invocations are given (e.g., no full clinic doctor command), so it sits between the 4 anchor (mostly executable, minor gaps) and 5.

4 / 5

Workflow Clarity

The 5-step Profiling Workflow has a clear sequence with explicit validation checkpoints and a feedback loop: "confirm in the profiler that the measured hotspot actually shrank", "Ship only at ≥10% improvement or once inside budget", and "If the regression persists, iterate and record a rollback plan", matching the 5 anchor.

5 / 5

Progressive Disclosure

This is a single-file skill (~24 lines) with no bundle files and no content that belongs in separate references; sections (Rules, Profiling Workflow) are well-organized, so per the rubric's simple-skill guideline it scores 5.

5 / 5

Total

19

/

20

Passed

Description

92%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: third-person imperative voice, multiple concrete actions, and an explicit 'Use when' clause with specific trigger terms. Keyword coverage is good but misses a few natural phrasings users would say (e.g., "site is slow", "page speed").

DimensionReasoningScore

Specificity

"split bundles, optimize assets, apply caching, fix Core Web Vitals regressions" lists multiple specific concrete actions with comprehensive coverage of the performance domain, matching the 5 anchor; only minor broadness in the lead phrase "reduces frontend/backend costs" keeps it from being argued lower, but no real coverage gaps exist.

5 / 5

Completeness

Explicitly answers both: what ("Profiles, reduces frontend/backend costs: split bundles, optimize assets, apply caching, fix Core Web Vitals regressions") and when ("Use when profiling Lighthouse/CI regressions, reducing bundle size, or fixing high CLS/LCP/TTI metrics") with concrete trigger phrases, matching the 5 anchor exactly.

5 / 5

Trigger Term Quality

Good natural keyword coverage ("Lighthouse", "CI regressions", "bundle size", "CLS/LCP/TTI metrics", "Core Web Vitals") including metric synonyms, but common user phrasings like "site is slow", "page speed", or "performance" are missing, so it falls between the 4 and 5 anchors.

4 / 5

Distinctiveness Conflict Risk

"fix Core Web Vitals regressions", "profiling Lighthouse", and "CLS/LCP/TTI" define a clear performance niche with distinct triggers unlikely to fire for unrelated skills, matching the 5 anchor for minimal conflict risk.

5 / 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
monkilabs/opencastle
Reviewed

Table of Contents

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