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

With no annotations, the description carries the burden of behavioral disclosure. It clearly states the body is discarded and the output is status/content type, but it omits network behavior such as redirects, timeouts, authentication, or error handling, which are relevant for a tool that fetches URLs.

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 two short sentences, front-loaded with the core function and a clear limitation. Every word earns its place; there is no redundancy or filler.

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 tool with nine optional parameters, no output schema, and no annotations, the description is incomplete. It covers only the URL case, does not explain how to choose among the many schema parameters, and does not describe expected status/error behavior.

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 description coverage is 100%, so the baseline is 3. The description adds little beyond saying 'public URL', which roughly maps to the url parameter, and does not help reconcile the other eight schema parameters with the URL-focused description.

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 operation: returning HTTP status and content type for a public URL, and 'Body discarded' distinguishes it from a full page fetch. It does not, however, differentiate it from sibling tools like fetch-status or browser-url-ok, so it stops short of a 5.

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 implies usage for lightweight URL checks by noting 'HTTP status and content type' and 'Body discarded'. It gives no explicit guidance about when to use this tool instead of fetch-status, browser-url-ok, or normalize-url, so the usage context is only implied.

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