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

With no annotations, the description carries the transparency burden. It does mention that the body is discarded, which is useful, but it does not describe network behavior, redirects, timeouts, error responses, or whether the request is read-only. The description is only partially transparent.

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 very concise and front-loaded: it states the main output in the first sentence and adds a critical caveat about the body in the second. No redundant words or filler are present.

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?

The tool has nine optional parameters, no output schema, and several functional siblings, but the description does not explain how the extra parameters relate to the core action, what the response shape looks like, or how errors are surfaced. The description is not complete enough for an agent to confidently invoke it in diverse situations.

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?

Although the schema has 100% description coverage, the overall tool description only relates to the URL parameter. The URL parameter description says 'normalize or cite,' which mismatches the stated HTTP status/content-type purpose, and the other eight parameters are given only 'discarded' or unrelated semantics.

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 core function: return HTTP status and content type for a public URL while discarding the body. It is specific enough to distinguish from body-fetching tools, though it lacks an explicit verb and does not reconcile with the many unrelated parameters in the schema.

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 no guidance on when to use this tool versus siblings like fetch-status, browser-url-ok, or normalize-url. The phrase 'Body discarded' implies it is not for content extraction, but no explicit use case or alternative is mentioned.

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