--- name: "Diagnose SEO" repo: https://github.com/calm-north/seojuice-skills source: https://github.com/calm-north/seojuice-skills/blob/HEAD/skills/diagnose-seo/SKILL.md license: "MIT" install: "npx skills add calm-north/seojuice-skills --skill diagnose-seo" page: https://100xlab.com/resources/agent-skills/calm-north-seojuice-skills--diagnose-seo--8v7zjh --- # Diagnose SEO Structured diagnostic framework for crawl issues, canonicalization errors, indexation problems, and rendering failures. ## Diagnostic Approach Technical SEO problems fall into four categories. Diagnose in this order — each layer depends on the previous one working correctly: 1. **Crawlability** — Can search engines find and access the pages? 2. **Indexability** — Are the pages allowed to be indexed? 3. **Renderability** — Can search engines see the full content? 4. **Signals** — Are the right signals (titles, structured data, links) in place? ## Layer 1: Crawlability Check these in order: ### robots.txt - Fetch `[domain]/robots.txt` and review the rules - Look for overly broad `Disallow` rules blocking important paths - Verify `Sitemap:` directive points to the correct sitemap URL - Check for different rules per user-agent (Googlebot vs others) **Common mistakes:** - `Disallow: /` blocking the entire site (often left from staging) - Blocking CSS/JS files that Googlebot needs for rendering - Blocking API or AJAX endpoints that load dynamic content - Staging robots.txt accidentally deployed to production ### XML Sitemap - Fetch the sitemap URL(s) and check: - Does it return 200? Is it valid XML? - Does it list all important pages? - Does it exclude pages that shouldn't be indexed (404s, redirects, noindex pages)? - Are `` dates accurate and recent? - For large sites: is there a sitemap index? ### Site Architecture - Pages should be reachable within 3 clicks from the homepage - Check for orphan pages (no internal links pointing to them) - Check for redirect chains (page A → B → C — should be A → C) - Check for redirect loops ### Server Response - Do all important pages return HTTP 200? - Check for unexpected 301/302 redirects - Check for soft 404s (page returns 200 but shows "not found" content) - Verify HTTPS is enforced (HTTP should 301 to HTTPS) ## Layer 2: Indexability ### Meta Robots / X-Robots-Tag - Check for `` on pages that should be indexed - Check HTTP headers for `X-Robots-Tag: noindex` - Common cause: CMS accidentally applying noindex to pagination, tag pages, or new pages ### Canonical Tags - Every page should have a `` pointing to itself (self-referencing canonical) - Check for canonical tags pointing to wrong pages (common in paginated content, filtered URLs) - Check for conflicting signals: canonical says page A, but noindex is set, or the page redirects **Canonical diagnosis checklist:** - [ ] Does the canonical URL match the actual URL? - [ ] Is the canonical URL accessible (returns 200)? - [ ] Does the canonical URL have the same content? - [ ] Is there only one canonical tag on the page? ### Duplicate Content - Check for the same content accessible at multiple URLs: - With and without trailing slash (`/page` vs `/page/`) - With and without `www` (`example.com` vs `www.example.com`) - HTTP vs HTTPS - URL parameters creating duplicate pages (`?sort=price`, `?page=1`) - Each duplicate set needs one canonical URL; all others should redirect or use canonical tags ## Layer 3: Renderability ### JavaScript Rendering - Does the page content appear in the raw HTML source? Or is it loaded via JavaScript? - If JS-rendered: does Googlebot see the full content? (Use URL Inspection tool in Search Console) - Check for content hidden behind click events, tabs, or accordions - Check for lazy-loaded content that only appears on scroll ### Core Content Visibility - Is the main content in the initial HTML? Or loaded async after page load? - Are important elements (titles, headings, product details) in the DOM on first render? - Check for content that requires login or cookies to view ## Layer 4: Signals ### Title Tags - Every page has a unique `` - Title includes the primary keyword - Under 60 characters (to avoid truncation in SERPs) - Descriptive and click-worthy ### Meta Descriptions - Every important page has a meta description - 150-160 characters - Includes target keyword and a value proposition - Unique per page ### Heading Structure - One H1 per page containing the primary keyword - Logical heading hierarchy (H1 → H2 → H3, no skips) - Headings describe section content (not decorative) ### Structured Data - Check for JSON-LD structured data appropriate to the page type - Validate with Google's Rich Results Test - Common types: Article, Product, FAQ, HowTo, BreadcrumbList, Organization ### Hreflang (multilingual sites) - Check for correct `hreflang` tags linking language variants - Verify reciprocal tags (page A points to B, B points back to A) - Check for `x-default` tag ## Output Format ### Technical SEO Diagnosis: [domain] **Summary** - Critical issues: [count] - Warnings: [count] - Passed checks: [count] **Findings by Layer** For each issue found: | Layer | Issue | Severity | Affected Pages | Fix | |-------|-------|----------|---------------|-----| | Crawlability | robots.txt blocks /blog/ | Critical | All blog pages | Remove `Disallow: /blog/` from robots.txt | | Indexability | Missing canonical tags | Warning | 15 pages | Add self-referencing canonicals | | ... | ... | ... | ... | ... | **Priority Fix List** Ordered by impact: 1. [Critical fix] — affects [n] pages, blocks [crawling/indexing/ranking] 2. [Warning fix] — affects [n] pages, reduces [signal quality] 3. ... --- > **Pro Tip:** Run the free [SEO Audit](https://seojuice.com/tools/seo-audit/) for a quick > technical check, the [Broken Link Checker](https://seojuice.com/tools/broken-link-checker/) > to find dead links, and the [Robots.txt Generator](https://seojuice.com/tools/robots-txt-generator/) > to fix crawl directives. SEOJuice MCP users can run `/seojuice:site-health` for a full > technical report and `/seojuice:page-audit [domain] [url]` to drill into specific pages.