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

The description discloses a key behavioral trait: the body is discarded and only HTTP status and content type are returned. It also constrains the input to public URLs. With no annotations, however, it omits details such as HTTP method, redirect handling, timeout/error behavior, and the fact that most schema parameters appear to be unrelated to the stated URL fetch.

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?

Two short sentences with zero wasted words; the main purpose is front-loaded and the side effect (body discarded) is stated immediately after. This is an exemplary concise description.

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 tool has nine optional parameters, no annotations, no output schema, and many closely related siblings, yet the description only addresses fetching a URL. It does not explain the role of the other parameters, how results are formatted, or when this tool is preferred over alternatives, leaving a substantial completeness gap.

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 an explanation. The tool description adds no parameter-level meaning beyond implying the url parameter is central, and it leaves the relationship of the other eight optional parameters unexplained. 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 returns HTTP status and content type for a public URL and discards the body. This gives a specific resource and observable output. However, it does not differentiate it from overlapping siblings 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 on when to use web-fetch versus sibling tools like fetch-status, normalize-url, or browser-url-ok. There are no prerequisites, exclusions, or conditions that would help an agent choose this tool.

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