Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so the safety profile is covered. The description adds meaningful behavior beyond that: following sitemap indexes and .gz up to 60 files, the 50,000-URL/50 MB limits, cross-host URL detection, and fetching sampled URLs as Googlebot expecting 200/non-redirect/non-noindex/self-canonical.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The purpose and scope are front-loaded in the first sentence, and the second sentence cleanly handles the 'contains' parameter. The first sentence is dense with a long checklist, but every item enumerated is a distinct audit output and earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description effectively enumerates what is audited and reported, and annotations cover safety. It is nearly complete, losing only a bit for not clarifying the 'sitemap' parameter or the shape of the response.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema covers only 50% of params, and the description compensates partially by explaining that 'contains checks whether given URLs are in the sitemaps' and describing the sampled Googlebot fetch behavior tied to 'sample'. But the 'sitemap' parameter has no description in either the schema or the text, leaving one parameter opaque.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Find and audit a site's XML sitemaps') and details the discovery mechanism (robots.txt, /sitemap.xml, indexes, .gz) plus what is checked. It is clearly distinguishable from the API-backed gsc_sitemaps/bing_sitemaps siblings by being a live crawl, though it never names those siblings.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage through the enumerated checks (status, URL counts, limits, lastmod, sampled Googlebot fetches), which tells an agent what it is for. However, there is no explicit when-to-use vs when-not guidance and no routing to gsc_sitemaps or bing_sitemaps for API-level sitemap data, so selection is left to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.