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

No annotations are provided, so the description carries the full burden. It discloses the HTTP method (HEAD) and the limited output (status only), but does not mention redirects, TLS behavior, error responses, rate limits, or whether the request is otherwise safe or side-effect-free.

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 main description is appropriately short and front-loaded, but the schema contains nine optional parameters with irrelevant and contradictory descriptions, adding noise rather than clarity. The overall tool definition is concise in word count but structurally confusing.

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 lacks an output schema, annotations, required parameters, and any explanation of what 'status' means (HTTP status code? status text?). The schema's unrelated fields further prevent an agent from understanding how to correctly invoke this tool. It is not complete enough for reliable use.

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 schema descriptions cover all parameters, they are fundamentally mismatched with the tool's purpose. The 'url' parameter is described as 'HTTPS URL to normalize or cite' rather than a URL to HEAD, and other parameters like city, zone, feed, json, and query are unrelated to fetching status. This is actively misleading.

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 verb 'HEAD' and the resource 'a public URL', and specifies the output as 'status only'. It is more specific than generic fetchers and helps distinguish from siblings like web-fetch or normalize-url, though the mismatched schema creates some ambiguity.

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 explicit guidance on when to use this tool versus alternatives such as browser-url-ok, web-fetch, or normalize-url. It only implies a status-only check, with no mention of required parameters, error cases, or when not to use it.

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