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image-optimization

Optimizes images for web performance using modern formats, responsive techniques, and lazy loading strategies. Use when improving page load times, implementing responsive images, or preparing assets for production deployment.

95

1.36x
Quality

93%

Does it follow best practices?

Impact

98%

1.36x

Average score across 3 eval scenarios

SecuritybySnyk

Passed

No known issues

SKILL.md
Quality
Evals
Security

Quality

Content

87%

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

This is a well-crafted, concise skill that provides actionable guidance for image optimization with executable code examples and clear structure. Its main weakness is the lack of a sequenced workflow with validation steps—particularly around the build pipeline where verifying output sizes against the stated performance targets would be valuable. The format selection table and optimization checklist are strong additions that make the skill practical.

Suggestions

Add a validation step after the Sharp build pipeline, e.g., checking output file size against performance targets and re-compressing if thresholds are exceeded.

Consider adding a brief sequenced workflow (e.g., 1. Audit current images → 2. Convert formats → 3. Validate sizes → 4. Implement responsive markup → 5. Verify with Lighthouse) to tie the individual sections into a coherent process.

DimensionReasoningScore

Conciseness

The content is lean and well-structured with tables, code examples, and a checklist. No unnecessary explanations of what image formats are or how browsers work—it assumes Claude's competence and every section delivers actionable information.

3 / 3

Actionability

Provides fully executable HTML and JavaScript code examples that are copy-paste ready. The format selection table, responsive images markup, Sharp pipeline code, and performance targets give concrete, specific guidance rather than vague descriptions.

3 / 3

Workflow Clarity

The checklist at the end provides a good summary of steps, but there's no clear sequenced workflow for the overall optimization process. There are no validation checkpoints—e.g., verifying output file sizes meet targets after running Sharp, or checking that the picture element renders correctly. For a build pipeline involving batch image processing, a feedback loop would be expected.

2 / 3

Progressive Disclosure

For a skill under 50 lines with no bundle files, the content is well-organized into clearly labeled sections that progress logically from format selection to implementation to targets to a checklist. No external references are needed given the scope.

3 / 3

Total

11

/

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.

This is a well-crafted skill description that clearly communicates specific capabilities (image optimization with modern formats, responsive techniques, lazy loading) and provides explicit trigger guidance via a 'Use when' clause. It uses third-person voice correctly and includes natural keywords that developers would use when seeking this functionality. The description is concise yet comprehensive, making it easy to distinguish from other skills.

DimensionReasoningScore

Specificity

Lists multiple specific concrete actions: optimizing images for web, using modern formats, responsive techniques, and lazy loading strategies. These are distinct, actionable capabilities.

3 / 3

Completeness

Clearly answers both what ('Optimizes images for web performance using modern formats, responsive techniques, and lazy loading strategies') and when ('Use when improving page load times, implementing responsive images, or preparing assets for production deployment').

3 / 3

Trigger Term Quality

Includes strong natural keywords users would say: 'images', 'web performance', 'responsive images', 'lazy loading', 'page load times', 'production deployment', 'assets'. Good coverage of terms a developer would naturally use.

3 / 3

Distinctiveness Conflict Risk

Clearly scoped to image optimization for web performance specifically, with distinct triggers like 'lazy loading', 'responsive images', and 'modern formats' that are unlikely to conflict with general web development or generic asset management skills.

3 / 3

Total

12

/

12

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.

Validation11 / 11 Passed

Validation for skill structure

No warnings or errors.

Repository
secondsky/claude-skills
Reviewed

Table of Contents

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