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

With no annotations, the description carries the disclosure burden and does so by naming the two returned fields and explicitly stating that the body is discarded. It also scopes usage to public URLs, implying no auth requirements. Redirects, timeouts, and error behavior are not covered, but they are secondary for this simple read operation.

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 with no filler. The core behavior is front-loaded and the key caveat 'Body discarded' is stated immediately. Every word earns its place.

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 basics are present: what is returned and that the body is discarded. However, with nine optional parameters, no output schema, no annotations, and a sibling list containing closely related tools, the description does not explain response shape, error behavior, or how to choose between web-fetch and alternatives. Those are noticeable gaps.

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 each parameter already has documentation and the baseline is 3. The tool description adds no parameter-level detail and does not explain how the eight non-URL optional parameters relate to the stated behavior. The schema's `url` description partially covers the main input, but it says 'normalize or cite' rather than explicitly 'fetch status and content type'.

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 that the tool reports HTTP status and content type for a public URL, and it explicitly says the body is discarded. This distinguishes it from a general content-fetching tool. It does not explicitly contrast with sibling fetch-status, though the content-type mention adds some differentiation.

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 'for a public URL' implies public, unauthenticated targets, and 'Body discarded' warns against using this tool when body content is needed. However, it never names alternatives such as fetch-status or browser-url-ok, so routing between closely related siblings is only implied.

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