largest-contentful-paint

Use when auditing slow page loads, heavy assets, or rendering delays related to Optimize largest contentful paint. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.

Quality

73%

Does it follow best practices?

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Securityby

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./skills/largest-contentful-paint/SKILL.md

Quality

Content

57%

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

The body is well-structured and uses progressive disclosure cleanly by deferring detail to references/rule.md. It is let down by repetition, restating of LCP basics, and a lack of executable guidance or an explicit measure-fix-verify loop in the body itself.

Suggestions

Remove the 'LCP is the most important Core Web Vital ...' explanatory opener and the duplicated technique list in Fix; keep Quick Reference as the single source of the fix techniques to tighten conciseness.

Add at least one copy-paste-ready snippet to the body (e.g. a `<link rel="preload" as="image" fetchpriority="high">` example) so the skill is actionable without opening the reference.

Make the workflow explicit with a numbered Check → Fix → Verify sequence and a re-test checkpoint (e.g. 're-measure LCP after each fix on a throttled mobile profile') so validation is a clear step rather than implied.

Dimension	Reasoning	Score
Conciseness	Mostly efficient sectioned content, but the opening line explains what LCP is ('the most important Core Web Vital ... measures when the main content becomes visible') which Claude already knows, and the Fix bullets repeat techniques already listed in Quick Reference.	2 / 3
Actionability	The body names concrete tools and targets ('Lighthouse or PageSpeed Insights', 'under 2.5s', 'preload', 'CDN', 'TTFB') but contains no executable code or commands — all implementation is deferred to references/rule.md — so it describes rather than instructs.	2 / 3
Workflow Clarity	The Check → Fix → Explain → Code Review sections imply a sequence and mention verification ('Verify the largest visible element renders within 2.5 seconds', 'describe the measurement method used to confirm the issue'), but there is no explicit numbered sequence with validation checkpoints or a measure → fix → re-test feedback loop in the body.	2 / 3
Progressive Disclosure	The body is a concise overview with well-signaled, one-level-deep navigation — 'see `references/rule.md`' — and the referenced file exists and does not nest further, giving easy navigation.	3 / 3
	Total	9 / 12 Passed

Description

90%

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-scoped description with explicit 'Use when' triggers, good natural keyword coverage, and a clear LCP niche. Its only weakness is that the named actions are somewhat abstract rather than a comprehensive list of concrete operations.

Dimension	Reasoning	Score
Specificity	It names the domain (LCP) and some actions — 'auditing slow page loads, heavy assets, or rendering delays' and 'Verify the actual bottleneck in DevTools, Lighthouse, or field data' — but the verbs are high-level rather than a comprehensive list of concrete actions like the score-3 anchor.	2 / 3
Completeness	It has an explicit 'Use when ...' trigger clause and states what the skill does (audit, verify the bottleneck, recommend changes), clearly answering both what and when.	3 / 3
Trigger Term Quality	It covers natural terms a user would say — 'slow page loads', 'heavy assets', 'rendering delays', 'Largest Contentful Paint', plus tools 'DevTools, Lighthouse, field data' — giving good keyword coverage rather than jargon-only phrasing.	3 / 3
Distinctiveness Conflict Risk	Tying the trigger to a specific Core Web Vital (LCP) carves a clear niche with distinct triggers, making overlap with generic page-speed skills unlikely.	3 / 3
	Total	11 / 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
metadata_version	'metadata.version' is missing	Warning

	Total	15 / 16 Passed

Repository: thedaviddias/Front-End-Checklist
Path: skills/largest-contentful-paint/SKILL.md
Commit: 48405aa

Reviewed: about 10 hours ago

Table of Contents

Discovery Implementation Validation

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