Optimize for search engine visibility and ranking. Use when asked to "improve SEO", "optimize for search", "fix meta tags", "add structured data", "sitemap optimization", or "search engine optimization".

SEO optimization Search engine optimization based on Lighthouse SEO audits and Google Search guidelines. Focus on technical SEO, on page optimization, and structured data. Evidence led audit workflow When a rendered page is available: 1. Run live Lighthouse SEO and Agentic Browsing checks when that capability is available; with Chrome DevTools MCP, use lighthouse audit . Use the results to localize rendered page failures. 2. Inspect signals Lighthouse cannot establish on its own: response headers, redirects, robots.txt , sitemap coverage, canonical consistency across page templates, structured data eligibility, and Search Console evidence when the user provides access. 3. Separate technical crawl/index findings from content quality and authority. Do not invent ranking factor weights or promise ranking changes. 4. Fix the source and re run the same checks. For indexation or ranking outcomes, report that search engine validation remains pending. If live tools are unavailable, use category specific Lighthouse CLI output plus direct source and HTTP inspection. A Lighthouse SEO score covers a useful subset of technical checks; it is not a prediction of rankings. Area What this skill can verify Crawl and index controls Technical configuration and consistency Rendered metadata and semantics Presence, validity, and page template issues Structured data Syntax and eligibility signals, not guaranteed rich results Core Web Vitals Link to measured field/lab evidence from the Core Web Vitals skill Content usefulness and authority Review quality, but do not assign synthetic ranking percentages Technical SEO Crawlability robots.txt: Meta robots: Canonical URLs: XML sitemap Sitemap best practices: Maximum 50,000 URLs or 50MB per sitemap Use sitemap index for larger sites Include only canonical, indexable URLs Update lastmod when content changes Submit to Google Search Console URL structure URL guidelines: Use hyphens, not underscores Lowercase only Keep short (< 75 characters) Include target keywords naturally Avoid parameters when possible Use HTTPS always HTTPS & security Security headers for SEO trust signals: On page SEO Title tags Title tag guidelines: Use 50–60 characters only as a rough linting proxy, not a pass/fail limit. Google truncates title links to fit the rendered device width, so preview width when tooling supports it. Describe the page topic naturally near the beginning Unique for every page Add the brand when it helps users distinguish the result Action oriented when appropriate Treat title link rewriting separately from truncation. Google may build a different title link from the visible page title, headings, anchor text, and other sources even when the <title is short; investigate accuracy and consistency rather than shortening it automatically. See [Google's title link guidance](https://developers.google.com/search/docs/appearance/title link). Meta descriptions Meta description guidelines: Use roughly 150–160 characters only as a linting proxy. Snippets are query and device dependent, and Google may select page content instead of the meta description. Use the page topic naturally Compelling call to action Unique for every page Matches page content Heading structure Heading guidelines: Make the primary page heading descriptive and the hierarchy unambiguous; do not fail a page solely because valid HTML contains more than one <h1 Logical hierarchy (don't skip levels) Include keywords naturally Descriptive, not generic Image SEO Image guidelines: Descriptive filenames with keywords Alt text describes the image content Compressed and properly sized WebP/AVIF with fallbacks Lazy load below fold images Internal linking Linking guidelines: Descriptive anchor text with keywords Link to relevant internal pages Reasonable number of links per page Fix broken links promptly Use breadcrumbs for hierarchy Structured data (JSON LD) Read [the structured data reference](references/STRUCTURED DATA.md) when the user requests schema markup or an audit surfaces a structured data issue. It contains Organization, Article, Product, FAQ, and Breadcrumb examples plus validation links. Describe visible, accurate content. Do not add a type or claim solely to obtain a rich result. Use the most specific applicable type. Keep identifiers and absolute URLs stable across renders. Validate rendered output. Passing syntax does not guarantee search engine eligibility or display. Agentic browsing and AI discoverability Keep these concepts separate: Lighthouse Agentic Browsing measures technical signals that help an assistant understand and interact with the rendered page. Current checks include the agent facing accessibility tree, optional llms.txt , and WebMCP registrations, schemas, and form coverage when present. Search indexing and ranking depend on search engine systems and cannot be inferred from the Agentic Browsing score. AI ingestion or citation is product specific. A technically browsable page or valid llms.txt file does not prove that an AI product will ingest, rank, or cite it. Prioritize semantic HTML, descriptive labels, crawlable content, accurate metadata, and clear page structure because they benefit people, search engines, and agents. Add WebMCP tools only when the application has useful actions to expose and the user wants that integration; validate tool names, descriptions, schemas, and form annotations with Lighthouse. Crawler controls are product specific Audit each documented user agent separately instead of applying a blanket "AI bot" rule: Control Documented purpose Effect of blocking OAI SearchBot ChatGPT search discovery Prevents page content from being included in ChatGPT summaries and snippets; a link and title may still surface through third party discovery PerplexityBot Perplexity search indexing Prevents that crawler from indexing the blocked content for search results Claude SearchBot / Claude User Claude search indexing / user directed retrieval May reduce search visibility / prevents retrieval for user directed requests Google Extended Controls certain Gemini training and grounding uses of content Google crawls Does not affect Google Search inclusion or ranking Training controls such as GPTBot and ClaudeBot are distinct from search and user fetch controls. GoogleOther is a generic crawler, not an AI search visibility switch. Verify current names and consequences in the vendors' maintained documentation: [OpenAI](https://help.openai.com/en/articles/12627856 publishers and developers faq), [Perplexity](https://docs.perplexity.ai/docs/resources/perplexity crawlers), [Anthropic](https://privacy.anthropic.com/en/articles/8896518 does anthropic crawl data from the web and how can site owners block the crawler), and [Google](https://developers.google.com/crawling/docs/crawlers fetchers/google common crawlers). llms.txt is optional llms.txt is an experimental proposal, not a cross vendor discovery standard. Lighthouse can validate the availability and shape of /llms.txt , but that does not show that a target product reads it. Add one only when the user requests it or a documented consumer supports it; do not recommend it ahead of crawlability, semantic HTML, accurate metadata, and useful content. Never treat it as a ranking or citation factor, duplicate the sitemap, or reorganize content solely to raise this audit. Mobile SEO Responsive design Tap targets Font sizes International SEO Hreflang tags Language declaration SEO audit checklist Critical [ ] HTTPS enabled [ ] robots.txt allows crawling [ ] No noindex on important pages [ ] Title tags present and unique [ ] Primary page heading is descriptive and the hierarchy is logical High priority [ ] Meta descriptions present [ ] Sitemap submitted [ ] Canonical URLs set [ ] Mobile responsive [ ] Core Web Vitals passing Medium priority [ ] Structured data implemented [ ] Internal linking strategy [ ] Image alt text [ ] Descriptive URLs [ ] Breadcrumb navigation [ ] Agentic Browsing failures reviewed when agent access matters Ongoing [ ] Fix crawl errors in Search Console [ ] Update sitemap when content changes [ ] Monitor ranking changes [ ] Check for broken links [ ] Review Search Console insights Tools Tool Use Google Search Console Monitor indexing, fix issues Google PageSpeed Insights Performance + Core Web Vitals Rich Results Test Validate structured data Live Lighthouse audit (Chrome DevTools MCP: lighthouse audit ) Rendered SEO and Agentic Browsing checks for agents Lighthouse CLI SEO audit fallback Screaming Frog Crawl analysis References [Google Search Central](https://developers.google.com/search) [Schema.org](https://schema.org/) [Core Web Vitals](../core web vitals/SKILL.md) [Web Quality Audit](../web quality audit/SKILL.md)

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