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

With no annotations, the description carries the behavioral disclosure burden. It explicitly states that the body is discarded and that only status/content type are returned, which is a meaningful behavioral constraint. It does not cover redirects, timeouts, or output format, but the core side-effect limitation is disclosed.

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 with no filler. It front-loads the purpose and then adds the critical behavioral constraint ('Body discarded'). 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?

Given the tool has 9 schema parameters and many close sibling tools, the description is too sparse to be complete. It does not explain the role of the non-URL parameters, how results are returned, or how this tool differs from fetch-status and other URL-checking siblings. The basic purpose is clear, but an agent cannot confidently select or invoke the tool across all relevant situations.

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 schema already documents every parameter. The tool description adds no parameter-level detail, but the baseline for high schema coverage is 3. The description also does not clarify why many unrelated-looking optional parameters exist in the schema, though this is not required at the baseline.

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 tool reports 'HTTP status and content type for a public URL' and adds that the body is discarded. Although it lacks an explicit verb like 'fetch', the resource and observable result are clear enough. It does not explicitly distinguish itself from the sibling 'fetch-status' tool.

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 provided on when to use web-fetch versus alternatives such as fetch-status, browser-url-ok, or playwright-url-ok. The phrase 'Body discarded' implies it is not for content extraction, but no explicit when-to-use or when-not-to-use guidance is given.

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