Attribution: Original skill by AgriciDaniel, MIT licensed. Cendis hosts this entry for discovery and install convenience; the upstream repo is the source of truth.
What it does
Runs a focused audit of a site’s technical SEO foundation — the layer that decides whether search engines and AI crawlers can find, fetch, render, and index your pages at all. This is the first thing to check when a site has good content but isn’t ranking.
When to use it
- After a major site migration or framework change
- When organic traffic drops with no content changes
- Before launching a new site or section
- When AI Overviews / AI Mode aren’t citing your pages and you want to know why
What it checks
Crawlability
- robots.txt validity and disallow rules
- XML sitemap presence, structure, and lastmod accuracy
- Internal link graph and crawl depth
- noindex / nofollow meta tags
- Pagination and faceted navigation handling
Indexability
- Canonical tag correctness (self-referencing, cross-domain, www vs apex)
- Duplicate content detection
- HTTP status codes (200/301/302/404/410)
- Soft 404s and thin content
Rendering
- Server-rendered vs JavaScript-rendered HTML diff
- Critical content present in initial HTML
- Hydration issues affecting bots
Performance (Core Web Vitals)
- LCP (Largest Contentful Paint) — target < 2.5s
- INP (Interaction to Next Paint) — target < 200ms
- CLS (Cumulative Layout Shift) — target < 0.1
Security and trust signals
- HTTPS enforcement
- HSTS header
- CSP and security headers
- Mixed content warnings
Mobile
- Viewport meta tag
- Tap target size
- Mobile-friendly rendering
Output
A structured report grouping findings by severity (Critical / High / Medium / Low) with the affected URL, the specific check that failed, and a recommended fix.
Why it matters
Technical SEO problems are silent killers. A missing canonical tag duplicates your page in the index. A broken sitemap means new content goes undiscovered. Slow LCP drops you in AI Overviews. None of these issues show up in your CMS or content workflow — they live in HTTP headers, render pipelines, and crawl budgets. This skill surfaces them in one pass.
License
MIT — original work by AgriciDaniel. Attribution preserved.