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

With no annotations, the description carries the full disclosure burden. It does disclose the key behavioral caveat that the body is discarded, which tells the agent not to expect page content. However, it does not mention redirects, error handling, timeouts, or whether a network request is always made, leaving important fetch semantics undisclosed.

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 appropriately concise: two short sentences with the core purpose front-loaded and the body-discard caveat immediately after. There is no filler or repetition.

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?

With 9 optional parameters, no output schema, no annotations, and many sibling tools, a 12-word description is not enough. It omits the return structure, the role of the non-URL parameters, and key constraints. An agent would have to infer too much to invoke this tool correctly and 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?

Schema description coverage is 100%, so each parameter already has its own explanation, such as 'HTTPS URL to normalize or cite' and 'JSON text to validate'. The description adds no parameter-level meaning and fails to clarify how non-URL parameters like city, path, zone, and query fit the stated URL-fetch behavior. Baseline 3 applies because the schema carries the documentation burden.

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 function: return HTTP status and content type for a public URL, with the body discarded. This is a specific verb+resource and matches the tool name. However, it does not differentiate from similar siblings like fetch-status or normalize-url, and it does not explain how the 9-parameter schema relates to the stated URL-only purpose.

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 provides no guidance on when to use web-fetch versus siblings such as fetch-status, browser-url-ok, or inspect-robots. It implies a status/content-type checking use case but gives no exclusions, conditions, or alternatives. An agent would have to guess which of the many similar tools to prefer.

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