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

With no annotations, the description must carry behavioral disclosure. It usefully discloses that the body is discarded and limits scope to public URLs, but it never mentions that the other schema properties (city, ref, json, path, feed, host) are ignored or how the tool behaves on redirects, errors, or timeouts.

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?

One tight sentence front-loads the core output and the body-discarded caveat; there is no filler. It is concise, though given the messy schema, a little more structure would have been useful.

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 7-parameter tool with no annotations and no output schema, this one-liner is incomplete. It does not say which parameters are accepted/ignored, what the return shape is, whether a URL is required, or how this differs from nearby sibling tools.

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 schema already describes every parameter, so the baseline is 3. However, the tool description adds no parameter-level guidance, and several schema descriptions conflict with the stated purpose (e.g., url is 'to normalize or cite', feed titles 'discarded', path is 'file path to check'), leaving the actual input for the fetch ambiguous.

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 names a specific action and resource: retrieving HTTP status and content type for a public URL, and explicitly says the body is discarded. That is clear enough to distinguish it from a general content-fetching tool, though it does not reference sibling tools such as fetch-status or browser-url-ok.

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?

No guidance is given about when to use web-fetch rather than the many URL/checking siblings (fetch-status, browser-url-ok, normalize-url). The description does not state required parameters, exclusions, or which schema properties actually drive the call.

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