XML sitemap — agent readiness

Why an agent cares

It is the one place a site states which URLs it wants found, so a broken or out-of-scope sitemap quietly costs coverage. Discovered from robots.txt Sitemap: directives, then followed through index files.

Adoption

Web baseline. Standard equipment on the web. Its absence is the exception rather than its presence.

Direction of travel: ► flat, as at 2026-07-28.

The sitemaps.org protocol, universally consumed by crawlers since 2006.

What we check

Absence is never a finding. Every check below runs only when this technology is detected, so a site that has not adopted this is not assessed on it and appears in no report. 8 of these 9 can fail it. In Lumar these appear once per site, in the site-wide results of each crawl.

Check	Severity	Raises	On whose authority
Sitemap Empty Document	high	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: the sitemap the site declares is served with no content in it, so it enumerates nothing an agent or crawler could follow. Distinct from malformed XML, which means a document that is there and won't parse: this one has no document at all, and the repair is different. Fix: publish the URLs at that address, or remove the Sitemap: line in robots.txt that promises them.
Sitemap Missing Namespace	high	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: the <urlset>/<sitemapindex> does not declare the required sitemaps.org 0.9 namespace, so strict parsers do not recognise the file as a sitemap and reject the whole thing. It covers both faults: a root with no xmlns at all, and one declaring a near-miss such as the https:// spelling of the sitemaps.org URL, which is the common case and a one-character fix. Fix: declare xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" on the root element, with http and not https.
Sitemap Malformed XML	high	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: a sitemap will not parse, so crawlers get nothing from it: either its XML isn't well-formed, or it's a .gz that doesn't decompress. A document that is simply not a sitemap is Sitemap Wrong Document Type instead, not this. Fix: repair the file (unclosed tags, unescaped & characters, or re-generate the gzip) and re-validate it. Sitemap Findings names the offending URL.
Sitemap Wrong Document Type	high	usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Related guidance in Sitemaps XML protocol. Bad: a URL declared as a sitemap (a robots.txt Sitemap: line, or a <loc> in a sitemap index) serves something that is not a sitemap in any permitted format, so an agent following the declaration gets no URLs. The file itself is often fine: a site pointing Sitemap: at its llms.txt has a valid llms.txt and an invalid declaration. Fix: point the declaration at a real sitemap, or remove it. Sitemap Findings names the URL.
Sitemap Relative Locs	medium	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: <loc> entries contain relative URLs, which the sitemaps.org protocol forbids, so crawlers drop those entries. Fix: make every <loc> a full absolute URL including scheme and host.
Sitemap Lists Another Host	medium	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: the sitemap lists URLs on a host it does not speak for, so crawlers drop those entries and the pages go undiscovered. Fix: serve a sitemap from that host, or have that host's robots.txt declare this one (cross-submission), e.g. Sitemap: https://shop.example.com/sitemap.xml.
Sitemap Too Large	medium	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: a single sitemap exceeds the protocol cap of 50,000 URLs / 50 MB, past which crawlers truncate or reject it. Fix: split it into multiple sitemaps referenced by a <sitemapindex>.
Sitemap Lists Above Its Directory	low	conformance, usability	specification: Sitemaps XML protocol
Supporting documents: Sitemaps XML protocol Required by Sitemaps XML protocol. Bad: the sitemap sits in a subdirectory but lists URLs above it, which the protocol scopes out (/catalog/sitemap.xml may not list /images/page). A sitemap only speaks for URLs beneath it, so those entries are ignored unless the file was submitted in Search Console. Fix: move the sitemap to the site root, or move the URLs under its directory.
Sitemap Partially Assessed	coverage note	nothing	our own coverage

Examples

Both run through the same checks as a live scan: the first passes, the second is flagged.

correctxml

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
    <loc>https://example.com/</loc>
    <lastmod>2026-01-01</lastmod>
  </url>
  <url>
    <loc>https://example.com/about</loc>
  </url>
  <url>
    <loc>https://example.com/products</loc>
  </url>
</urlset>

present but wrongxml

<?xml version="1.0" encoding="UTF-8"?>
<urlset>
  <url>
    <loc>/</loc>
  </url>
  <url>
    <loc>/about</loc>
  </url>
</urlset>

Specifications

Document	Revision	Kind
Sitemaps XML protocol	Version 0.9	specification

Last re-read against the published documents: 2026-10-05.