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

The description discloses that the body is discarded and that the URL must be public, which is useful. However, with no annotations, the description carries the full burden but fails to explain what happens with the other parameters (e.g., whether they are ignored, validated, or transformed). There is no mention of side effects, rate limits, or authentication requirements beyond 'public URL'.

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: two sentences with no filler. It front-loads the primary function and immediately states the body-discard behavior. Given the tool's apparent simplicity (though actual scope is broader), the brevity is appropriate and well-structured.

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 description is incomplete for a tool with nine parameters and no output schema. It does not explain how the tool handles the non-URL parameters, nor does it describe the return format (beyond status and content type). The description does not account for the full operational scope implied by the parameter list, leaving agents guessing about expected behavior for most inputs.

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 each parameter's meaning (e.g., 'City name for a public weather hint'). The tool description adds no additional context about parameters—it only mentions a URL, leaving the purpose of the other eight fields unexplained. This meets the baseline of 3 but does not exceed it.

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 clear core purpose: fetch a public URL and return HTTP status and content type, discarding the body. However, the parameter set includes nine unrelated fields (city, zone, feed, json, path, query, etc.) that are never mentioned in the description, creating ambiguity about whether the tool actually does more than presented. It also does not differentiate from siblings like 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?

There is no guidance on when to use this tool versus alternatives. No mention of scenarios where web-fetch is preferred over fetch-status, normalize-url, or other siblings. The description gives no exclusions or context for selecting it.

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