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

Goes well beyond the annotations: it discloses the cost model (1 credit per sitemap file read, usually 1 total, never per URL), the non-fetching behavior, and the specific limitations (no content, misses undeclared pages). The credit side effect also explains why readOnlyHint is false despite the discovery-only behavior, so there is no contradiction.

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?

Front-loaded with the core purpose and packed with useful detail in a small footprint; the em-dash-heavy run-on sentence is dense but every clause earns its place. Slightly harder to scan than two clean sentences.

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 supplies the return shape (discovery method, totals, up to `limit` URLs, section names) as well as cost and coverage caveats. An agent has everything needed to decide and invoke correctly.

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 description coverage is 100%, so all three parameters are already documented. The description restates `limit` ('up to `limit` URLs') and adds that totals still count all URLs, but does not mention the `search` filter or add syntax beyond the schema, so baseline 3 applies.

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?

Specific verb+resource ('List every URL a site declares in its sitemaps') with the mechanism named (robots.txt, well-known paths, index files walked to children). It is immediately distinguishable from siblings like crawl_site and scrape_urls, which it explicitly says do something else.

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?

Explicit ordering guidance ('Use it first... before crawl_site or create_project') plus clear exclusions: it cannot read page content (scrape_urls or crawl_site do) and misses pages a site links to but does not declare. Both when-to-use and when-not-to-use are covered with named alternatives.

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