Read the sitemap

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses a nontrivial behavior: following the sitemap index when present, and clarifies the source is the declared sitemap rather than actual links. It does not mention network-fetch behavior or error handling, but for a straightforward read-only listing tool this is adequate.

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?

Two concise, purposeful sentences. The first states the core action and index-following behavior; the second adds practical context. There is no redundant or filler language.

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?

For a simple two-parameter tool with no output schema, the description plus schema provides enough for an agent to call it correctly: what it lists, how it handles indexes, and why it is useful. A brief statement of return format would have been nice, but it is not necessary to invoke the tool 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?

The input schema has 100% coverage for both parameters, including defaults and constraints, so the description does not need to add much. It adds no parameter-specific meaning beyond what the schema already provides, which justifies the baseline score.

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?

The description uses a specific verb ('List') and a clear resource ('URLs a site declares in its sitemap'), and adds a precise behavioral detail about following sitemap indexes. It also implicitly distinguishes itself from crawl-oriented siblings by noting the sitemap often differs from what the site actually links to.

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 gives a clear use case: to see what the site thinks it publishes. It also implies this is not the tool for discovering actual linked URLs, but it does not explicitly name alternatives such as crawl_site or link_graph, so the guidance stops short of a full when-to-use/when-not-to-use statement.

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