A sitemap is a discovery source, not an index receipt
A sitemap describes URLs you want search engines to discover. Submitting one does not guarantee crawling or indexing. Bostic's sitemap check answers narrower questions about the sitemap and the URLs it could inspect; it is not a copy of Google's index.
Begin with the saved target, start time and scope. Discovery can find many URLs before their individual checks finish. A counter of discovered URLs therefore must not be read as the number already validated.
Read partial results as partial results
For a large site, open the running report to inspect completed checks while the rest continue. Read the progress count and any preliminary-result label together. A plan boundary, inaccessible sitemap or interrupted job can leave the report incomplete; a finished-looking table alone does not prove full coverage.
When comparing with a crawler report, check the crawler's scope too. A limited crawl and a larger sitemap inventory describe different sets of URLs. Their counts should not be forced to match.
Three responses, three different decisions
These are illustrative response patterns, not measurements from a customer site. Open the row's evidence and final URL before taking action. A page that opens in your browser can still behave differently for a server-side request.
Confirmed 404 or 410
Check whether the URL should exist. Restore it, update the source link or remove an obsolete sitemap entry as appropriate.
Redirect to another URL
Inspect the destination and the redirect chain. Decide whether the sitemap should point directly to the intended final page.
Timeout, rate limit or access block
Treat the evidence as uncertain. Check server access rules and retry when allowed; do not delete a working page just because this request could not verify it.
Close the loop with evidence
Keep the original report as your reference. After changing an affected page, use a focused check where that finding supports it. A page-level check cannot establish that every sitemap entry is now correct; structural sitemap changes may need a new sitemap run.
Compare reports only after reading their scope, timestamps and completion state. Track unresolved and unverified findings separately so uncertainty does not become a false success or a false failure.