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 usefully states that the body is discarded and that the URL must be public. However, it does not describe network semantics such as whether it performs a GET request, follows redirects, or has no side effects.

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 extremely concise, with only two sentences and no wasted words. The primary outcome is stated first, and the secondary behavioral note about the body being discarded is clearly separated and relevant.

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 nine optional parameters, no required parameters, no output schema, and no annotations, the description is far too sparse. It does not explain the return format, which parameters actually drive the fetch, or how the other parameters should be treated, leaving an agent without enough information to invoke the tool confidently.

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 input schema has high description coverage (100%), so the baseline is 3. The description adds meaning for the URL parameter by tying it to HTTP status/content type, but it does not clarify how the other eight optional parameters relate to the stated purpose, leaving potential ambiguity.

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's core outcome: it returns HTTP status and content type for a public URL. 'Body discarded' adds useful specificity. However, it does not differentiate this tool from siblings like fetch-status or browser-url-ok, whose purpose overlaps.

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 gives no guidance on when to use web-fetch versus the many sibling tools. It implies a use case for checking a public URL, but does not mention exclusions, alternatives, or which sibling should be chosen for other URL-fetching needs.

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