performance-optimization

Diagnose and fix web performance issues including Core Web Vitals (LCP, INP, CLS), bundle size, asset optimization, render performance, and runtime efficiency. Use this skill whenever the user wants to improve page speed, fix Core Web Vitals, optimize assets, reduce bundle size, debug slow renders, or systematically improve a site's performance. Triggers on performance, page speed, Core Web Vitals, LCP, INP, CLS, FID, TTFB, bundle size, code splitting, image optimization, lazy loading, render blocking, slow page, performance audit, Lighthouse score. Also triggers when traffic or conversion is dropping due to perceived slowness.

Quality

—

Does it follow best practices?

Impact

—

No eval scenarios have been run

Securityby

Advisory

Suggest reviewing before use

Quality

Content

100%

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

A high-quality body: concise, actionable, with a measured and iterated workflow and clean progressive disclosure to three real reference files. It assumes Claude's competence and adds only domain-specific value (thresholds, named APIs, failure patterns).

Dimension	Reasoning	Score
Conciseness	Lean and dense throughout — targets, causes, and fixes are stated directly with no padding about what a metric is or how libraries work; not the score-2 case because there is no unnecessary explanation to tighten.	3 / 3
Actionability	Gives concrete, executable specifics — named thresholds (LCP <2.5s, INP <200ms, CLS <0.1), real APIs (`scheduler.yield()`, `font-display: swap`, `loading="lazy"`, `import { fn } from 'lib'`), and named tools (Lighthouse, WebPageTest, CrUX) — copy-paste ready rather than abstract.	3 / 3
Workflow Clarity	The 7-step Workflow is clearly sequenced with an explicit re-measure feedback loop (implement → re-run Lighthouse/RUM → iterate), providing the validation checkpoints the rubric requires; not capped at 2 because measurement-after-fix checkpoints are present.	3 / 3
Progressive Disclosure	The body is an overview that points to three well-signaled, one-level-deep references — audit-template.md, optimization-checklist.md, optimization-playbook.md — all verified to exist, each with a one-line purpose, so content is appropriately split with easy navigation.	3 / 3
	Total	12 / 12 Passed

Description

100%

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, well-rounded description: it states concrete capabilities, lists natural trigger terms, gives explicit when-to-use guidance, and carves out a distinct niche. No notable weakness to address.

Dimension	Reasoning	Score
Specificity	Names multiple concrete actions — 'Diagnose and fix web performance issues', 'optimize assets', 'reduce bundle size', 'debug slow renders' — matching the multi-action anchor rather than the single-domain score 2.	3 / 3
Completeness	Explicitly answers both what ('Diagnose and fix web performance issues including...') and when ('Use this skill whenever the user wants to improve page speed...'), with explicit trigger guidance, so it clears the cap at 2.	3 / 3
Trigger Term Quality	Strong coverage of natural terms a user would say ('page speed', 'Lighthouse score', 'slow page', 'image optimization', 'lazy loading', 'Core Web Vitals'), plus the deprecated-but-common FID; no common variation is missing.	3 / 3
Distinctiveness Conflict Risk	Occupies a clear niche (web performance / Core Web Vitals) with distinct triggers; the 'When NOT to use' section in the body further separates it from qa-testing, seo-technical, and code-review-web, making mis-triggering unlikely.	3 / 3
	Total	12 / 12 Passed

Validation

93%

Warnings & errors only

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

Validation — 15 / 16 Passed

Validation for skill structure

Criteria	Description	Result
frontmatter_unknown_keys	Unknown frontmatter key(s) found; consider removing or moving to metadata	Warning

	Total	15 / 16 Passed

Repository: rampstackco/claude-skills
Commit: f1bc195

Reviewed: 9 days ago

Table of Contents

Discovery Implementation Validation

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