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

With no annotations, the description carries the full burden, and it does disclose that the body is discarded. However, it does not mention whether redirects are followed, what happens on errors, whether authentication is needed, or the exact return format, leaving important behavior unspecified.

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 prose description is concise and each sentence carries meaning, explicitly stating the result and the discarded body. However, the overall structure is undermined by the bloated and unrelated input schema, though that is more a completeness issue than a conciseness issue.

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 description is not complete enough to call the tool correctly. There is no output schema and no stated return format, all nine parameters are optional, and the schema does not clarify which parameter should be used for the described URL fetch. The tool definition leaves too much essential context unspecified.

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 parameter descriptions are severely inconsistent with the tool's stated purpose. The 'url' parameter is described as 'HTTPS URL to normalize or cite' rather than to fetch, and the other seven parameters (ref, city, feed, json, path, zone, query) are entirely unrelated to HTTP status or content type. This gives an agent no reliable mapping from inputs to expected behavior.

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 states a specific action result (HTTP status and content type for a public URL) and explicitly mentions body is discarded, but the input schema introduces eight unrelated optional parameters with contradictory descriptions. This muddles the tool's actual purpose and makes it unclear what the tool is really for.

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 phrase 'Body discarded' implicitly tells the agent not to use this tool to retrieve page content, but there is no explicit guidance about when to use this tool versus siblings like fetch-status, browser-url-ok, or normalize-url. No alternative tools or conditions are mentioned.

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