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

Annotations already cover safety (readOnly, idempotent, non-destructive), so the description's job is extra context — and it delivers cost ('1 credit; free when nothing is found') and mechanism (sitemaps + start page links), which tells the agent the result set is bounded by what the site exposes. It doesn't mention pagination or result ordering beyond the optional search ranking.

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 short sentences, both front-loaded: the scope and data source come first, the credit caveat second. No filler or restatement of the title.

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 read-only, single-required-parameter tool with no output schema, the description conveys what is returned (URLs), where they come from, and the billing model. The only real gap is the unexplained limit parameter and how results are ordered absent a search phrase.

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 coverage is 60%, with search, exclude_paths and include_paths self-documented in the schema. The description reinforces the search-ranking behavior but adds nothing for 'limit' (cap 5000) or the path-filter regexes, so it does not fully compensate for the documented gap.

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 and resource ('List a website's URLs') plus a precise scope: sitemaps plus the start page's links. That distinguishes it from navigation-style siblings like search or webpage, though it never names crawl, which is the nearest alternative for follow-up content fetching.

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?

'Optionally ranked by a search phrase' implies a discovery use case, but the description never states when to use map versus crawl, search, or extract, and gives no exclusions. The agent must infer the routing decision from sibling names alone.

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