tessl-labs/web-accessibility-essentials
Web accessibility from the start — always apply semantic HTML, form labels, ARIA attributes, keyboard navigation, live regions, alt text, and heading hierarchy when building any UI component
93
90%
Does it follow best practices?
Impact
98%
1.24xAverage score across 5 eval scenarios
Passed
No known issues
Quality
Discovery
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 an excellent skill description that clearly articulates specific accessibility techniques, covers multiple frontend frameworks users would naturally mention, and explicitly states both what the skill does and when it should apply. The proactive framing ('even when the user does not mention accessibility') is particularly strong for ensuring the skill activates appropriately.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'ARIA landmarks, form labels, keyboard navigation, focus management, live regions, semantic HTML, heading hierarchy, alt text, and color contrast' - these are all specific, actionable accessibility techniques. | 3 / 3 |
Completeness | Clearly answers WHAT (apply ARIA landmarks, form labels, keyboard navigation, etc.) AND WHEN ('whenever you build or modify any HTML, React component... or frontend UI' and 'applies to ALL frontend work — even when the user does not mention accessibility'). The 'when' is explicit and comprehensive. | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms including framework names users would mention ('React component, Vue component, Svelte component, Angular template'), file types ('HTML'), and the domain ('frontend UI', 'accessibility'). These match how developers naturally describe their work. | 3 / 3 |
Distinctiveness Conflict Risk | Clear niche focused specifically on accessibility in frontend development. The combination of accessibility-specific techniques (ARIA, focus management, live regions) with frontend frameworks creates a distinct trigger profile unlikely to conflict with general coding or design skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
77%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a strong, highly actionable accessibility skill with excellent code examples and clear anti-patterns. The comprehensive checklist provides good validation guidance. However, the document is lengthy and could be more token-efficient by removing redundant explanations and splitting detailed patterns into separate reference files.
Suggestions
Remove redundant phrases like 'not div soup' that appear multiple times, and trim explanatory text that Claude already knows (e.g., 'Screen readers depend on these to navigate')
Consider splitting detailed sections (Forms, Modals, Live Regions) into separate reference files with SKILL.md providing a concise overview and links
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is comprehensive but includes some redundant explanations (e.g., 'Screen readers depend on these to navigate') and could be tightened. The 'Golden Rule' section repeats concepts that are detailed later, and some explanations like 'not div soup' appear multiple times. | 2 / 3 |
Actionability | Excellent actionability with fully executable HTML, CSS, JSX, and TypeScript code examples throughout. Every pattern includes copy-paste ready code with proper attributes, and anti-patterns are clearly marked with 'NEVER' directives. | 3 / 3 |
Workflow Clarity | For an instruction-based skill covering multiple UI patterns, the workflow is exceptionally clear. Each section follows a consistent pattern (requirement → code example → anti-patterns), and the comprehensive checklist at the end provides explicit validation steps for every component type. | 3 / 3 |
Progressive Disclosure | The content is well-organized with clear sections and a table of contents via headings, but it's a monolithic document (~400 lines) that could benefit from splitting detailed patterns (modals, forms, tables) into separate reference files. The verifiers section references external files but the main content doesn't leverage progressive disclosure. | 2 / 3 |
Total | 10 / 12 Passed |
Validation
90%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 10 / 11 Passed | |
Reviewed
Table of Contents