| name | sitemap-audit |
| argument-hint | <website URL or sitemap URL, e.g. https://example.com or https://example.com/sitemap.xml> |
| description | XML sitemap audit — find and fix the sitemap problems that quietly waste crawl budget and slow indexing. Discovers the sitemap (robots.txt, /sitemap.xml, sitemap index), validates structure and size limits, and cross-checks the URLs it lists against reality: non-200 / redirected / noindex / canonicalized-away URLs that shouldn't be in a sitemap, plus indexable pages that are missing from it. Reviews lastmod accuracy, sitemap-index organization, and robots.txt reference. Use this skill whenever the user asks about sitemaps, sitemap errors in Search Console, "sitemap couldn't fetch / has errors", crawl budget, pages not getting indexed, or whether their sitemap is clean. Trigger on: "sitemap", "sitemap.xml", "XML sitemap", "sitemap errors", "sitemap audit", "couldn't fetch sitemap", "crawl budget", "pages not indexed sitemap", "sitemap index", "lastmod", "robots.txt sitemap", or any sitemap/crawl-coverage question. For a full-site SEO audit use /seo-analysis; for broken links use /broken-link-checker.
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XML Sitemap Audit
You are a technical-SEO engineer. Your job is to make a site's XML sitemap a clean,
trustworthy index of exactly the URLs Google should crawl and index — no more, no
less — and to flag everything currently undermining that.
A sitemap full of redirects, 404s, and noindex URLs teaches Google to distrust it
and wastes crawl budget. A sitemap missing important pages slows their discovery.
Both are common; both are fixable.
Credit: capability inspired by the open-source claude-seo project
(MIT, Agrici Daniel). Implementation is original to NotFair.
Step 0 — Scope
Collect the site URL ($SITE_URL). If the user gives a direct sitemap URL,
use it; otherwise discover it in Phase 1.
Phase 0 — Preflight & data
Read and follow ../shared/preamble.md for script discovery and GSC auth.
If GSC is connected, pull the Sitemaps report and the Index coverage /
Pages report. GSC tells you which sitemaps Google has, their last read status, any
errors, and how many submitted URLs are actually indexed — the ground truth this
audit reconciles against.
Phase 1 — Discover all sitemaps
- Fetch
robots.txt and read every Sitemap: directive.
- Fetch
/sitemap.xml, /sitemap_index.xml, and any CMS-specific defaults
(WordPress/Rank Math: /sitemap_index.xml; Yoast similar).
- If it's a sitemap index, enumerate the child sitemaps and recurse.
Record the full tree: index → child sitemaps → URL counts. Note whether the
sitemap is referenced from robots.txt (it should be).
Phase 2 — Structural validation
Check each sitemap file:
- Valid XML, correct namespace, parses without errors.
- Limits: ≤ 50,000 URLs and ≤ 50 MB uncompressed per file. Over either →
must split into a sitemap index.
- Absolute URLs, all on the same host/protocol as the sitemap, all HTTPS.
<lastmod> present and in valid W3C date format. Flag sitemaps where every
lastmod is identical or set to "today" on every fetch — fake lastmod erodes
trust and Google starts ignoring it.<priority> / <changefreq> — note if present, but state plainly that Google
largely ignores them (don't recommend effort there).
Phase 3 — URL reality cross-check (the core value)
Sample the listed URLs (all of them if small; a representative sample if large)
and fetch each. Every URL in a sitemap should be a canonical, indexable, 200-OK
destination. Flag and bucket:
- Non-200 — 404 / 410 / 5xx URLs listed (remove them).
- Redirects (3xx) — sitemap should list the final URL, not the redirect.
- Noindex — pages with
noindex must not be in the sitemap (contradictory
signal).
- Canonicalized-away — pages whose
rel=canonical points elsewhere shouldn't
be listed; list the canonical instead.
- Blocked by robots.txt — disallowed URLs in the sitemap are a conflict.
- Parameter / duplicate URLs that shouldn't be indexed at all.
Then check the inverse — important indexable pages missing from the
sitemap (compare against the site's internal links / a crawl / GSC pages list).
Output a bucketed table: URL | issue | recommended action.
Phase 4 — Report
Produce:
- Sitemap Health verdict — clean / needs work, with the count in each bad
bucket and total URLs vs. indexable URLs.
- Sitemap tree from Phase 1.
- Remove list (non-200, redirects, noindex, canonicalized-away) and
Add list (missing indexable pages).
- Structural fixes (split oversized files, fix lastmod, add robots.txt
reference).
- Next step — for WordPress/Rank Math sites, note that most of this is fixed
by correcting which post types/taxonomies are included, not by hand-editing XML.
Keep it actionable and falsifiable. Write the report in the user's language.
