Browse reusable Agent Skills, each with a clear purpose and practical guidance.
Use when applies to all HTML documents. Always check the very first line of the raw HTML source (view-source: or DevTools > Network > Response). In SSR frameworks, check the root HTML template (e.g., _document.tsx in Next.js, index.html in Vite/Vue, application.html.erb in Rails). The doctype is not a tag — it is a declaration and does not need a closing tag.
Use when reviewing scripts, client components, bundles, or runtime behavior related to Minimize costly DOM read/write operations. Inspect both source code and the browser execution path so fixes target the real bottleneck or bug. In React, repeated requestAnimationFrame-driven state updates across multiple mounted components are a valid performance smell when visible in the source.
Use when reviewing templates, rendered HTML, or shared components related to Make drag and drop accessible. Validate the final browser-facing markup, not just the source framework abstraction.
Use when auditing a site's meta tag uniqueness, generating page-specific meta descriptions, or reviewing CMS templates that inject the same description globally.
Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use unique IDs for active elements. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.
Use when reviewing rendered HTML, interactive components, or design-system patterns related to Use unique IDs for ARIA references. Check native semantics first, then inspect keyboard behavior, focus flow, accessible names, and screen-reader output where relevant.
Use when auditing slow page loads, heavy assets, or rendering delays related to Remove duplicate JavaScript libraries. Verify the actual bottleneck in DevTools, Lighthouse, or field data before recommending changes.
Use when reviewing CI coverage, automated checks, or test strategy related to Implement end-to-end testing. Focus on whether the rule is continuously verified, not just documented.
Use when auditing a blog, news site, or YMYL content site for trust signals, drafting editorial policy page content, or evaluating whether a site meets Google's quality rater trustworthiness criteria.