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

The description goes beyond the readOnlyHint annotation by stating that page content is not fetched and that private/internal hosts are blocked. This gives useful behavioral expectations without needing to inspect implementation details.

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 a single, well-structured sentence that efficiently communicates purpose, scope, and a key constraint. There is no redundant or extraneous text.

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 one-parameter tool with no output schema, the description covers the main contextual points: what it does, what it does not fetch, and blocking behavior. It is complete enough for an agent to decide and call the tool, though an explicit note about the return format would be a minor enhancement.

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 schema already provides a clear description for the url parameter ('The http/https URL to map') with 100% coverage, so the baseline applies. The tool-level description adds the same-origin context but does not significantly expand parameter semantics beyond what the schema states.

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 clearly states the tool discovers same-origin URLs linked from a page and calls it a site map. It also explicitly notes no page content is fetched and private/internal hosts are blocked, which distinguishes it from content-scraping tools like scrape_page or read_url.

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 clear context that this tool is for link discovery and not for page content retrieval, and the blocking note helps set expectations about when results may be limited. It does not explicitly name alternative tools, but the context is strong enough to guide selection among the siblings.

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