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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It explains the lookup order (robots.txt first, then /sitemap.xml), how sitemap indexes are surfaced, and the exact cost per call. This goes beyond a simple 'list pages' statement, though failure modes and exact response structure are not described.

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 description is three sentences with no wasted words. It front-loads the core result and discovery method, then gives use case and cost. Every sentence adds useful information without repeating schema content.

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 two-parameter tool with no output schema, the description covers the discovery mechanism, the sitemap index follow-up case, the intended use case, and cost. It could describe the exact return format in more detail, but the operational behavior is sufficiently clear for an agent to call it 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 the baseline is 3. The description adds meaning by clarifying that url can be a site root or a direct sitemap URL, and by explaining how sitemap indexes affect follow-up calls. The limit parameter is already fully documented in the schema with default and maximum values.

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 identifies a specific verb and resource: enumerate the pages a site declares in its sitemap, with last-modified dates. This clearly distinguishes it from sibling tools like request_data or resolve_url by focusing on sitemap-based site enumeration rather than generic HTTP requests or URL resolution.

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 explicitly states when to use the tool: to enumerate a documentation set or blog archive before deciding what to read, instead of crawling blindly. It also explains that a sitemap index is reported as such, so the agent knows to call again for child sitemaps. It does not name explicit alternatives but gives enough contextual guidance for selection.

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