js-file-size

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

Quality

65%

Does it follow best practices?

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tessl review fix ./skills/js-file-size/SKILL.md

Quality

Content

61%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.

The body is well-structured and token-efficient, with a clean single-reference progressive-disclosure design, but it offers high-level direction rather than executable guidance and lacks explicit validation checkpoints in its workflow. Adding a concrete measurement command and a verify→fix→re-measure loop would meaningfully raise actionability and workflow clarity.

Suggestions

Add at least one executable measurement snippet (e.g. a Lighthouse CLI or webpack-bundle-analyzer command) so the Check step is copy-paste ready rather than descriptive.

Insert an explicit validation checkpoint between Check and Fix, e.g. 'Confirm the oversized bundle in DevTools Coverage / Lighthouse before changing code; re-measure after the fix to verify TTI/INP improved'.

Fix or remove the empty '## Code Examples' heading and the malformed dynamic-import/tree-shaking snippets in references/rule.md so the deferred material is actually executable.

Dimension	Reasoning	Score
Conciseness	The body is lean with tight Quick Reference bullets and short Check/Fix/Explain/Code Review sections; the only trimmable excess is the opening sentence restating that excessive JS slows pages, which Claude already knows.	4 / 5
Actionability	Gives a concrete 200KB threshold and names techniques (code-splitting, tree-shaking, dependency audits), but the body provides no executable code or commands and the deferred reference examples are incomplete, leaving key execution details missing.	3 / 5
Workflow Clarity	A Check→Fix→Explain→Code Review sequence is present, but there are no explicit validation checkpoints or a validate→fix→retry feedback loop in the body, even though the skill asks the user to confirm a bottleneck before recommending changes.	3 / 5
Progressive Disclosure	The body is a concise overview with a clearly signaled one-level-deep pointer to references/rule.md (a real file), and content is appropriately split; minor gaps keep it just below the exemplary anchor.	4 / 5
	Total	14 / 20 Passed

Description

70%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.

The description pairs a clear 'Use when…' trigger with concrete measurement-context terms and a distinct performance niche, but under-specifies the actual optimization actions the skill performs, leaning on the skill title for the 'what'. Tightening specificity would lift it from good to comprehensive.

Suggestions

Replace the generic 'Optimize JavaScript bundle size' phrasing with concrete actions the skill performs, e.g. 'Audit JS bundles for files over 200KB and apply code-splitting, tree-shaking, and dependency audits to reduce them'.

Add common natural synonyms such as 'bundle size', 'JavaScript payload', or 'KB' so the trigger matches more user phrasings.

Lead with the 'what' before the 'when' so the capability is stated explicitly rather than only implied by the skill name.

Dimension	Reasoning	Score
Specificity	Names the JS-bundle-size domain and a couple concrete actions ('auditing slow page loads', 'Verify the actual bottleneck in DevTools, Lighthouse, or field data') but does not enumerate the skill's actual optimization actions (code-splitting, tree-shaking), so coverage is not comprehensive.	3 / 5
Completeness	Provides an explicit 'Use when…' trigger and a 'what' (optimize JavaScript bundle size), but the 'what' is largely the skill name restated rather than concrete capability actions, so it sits just below the fully explicit anchor.	4 / 5
Trigger Term Quality	Includes natural phrases users say ('slow page loads', 'heavy assets', 'rendering delays', 'DevTools', 'Lighthouse', 'field data') but omits common synonyms like 'bundle size', 'JavaScript', or file extensions, leaving a few natural terms missing.	4 / 5
Distinctiveness Conflict Risk	Targets a distinct performance niche (JS bundle size) with specific measurement triggers, with only minor overlap risk against sibling frontend-performance skills.	4 / 5
	Total	15 / 20 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/js-file-size/SKILL.md
Commit: 30756a7

Reviewed: 4 days ago

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