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

The description adds one important behavioral trait—'Body discarded'—which sets expectations about output scope. However, with no annotations present, it does not disclose other relevant behaviors such as whether external network requests are made, timeout behavior, redirects, or response failure modes.

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 short and front-loaded, with no wasted words. It would earn a 5 if it included the missing param guidance without sacrificing brevity.

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 no annotations and no output schema, the description carries the burden of explaining the tool, but it leaves important usage details unstated. The diverse schema parameters and the lack of distinction from sibling tools make this incomplete for safe and correct selection.

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?

Although the schema has descriptions for every parameter, those descriptions are inconsistent with the tool's stated purpose (e.g., url says 'normalize or cite', city refers to weather hints, json is for validation). The tool description does not clarify which parameter should actually be used for the URL fetch or how the unrelated parameters relate to calling this tool.

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 that the body is discarded. It is specific enough to convey the core behavior, though it does not differentiate web-fetch from the sibling fetch-status or other URL-related tools.

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 about when to use this tool versus siblings like fetch-status, browser-url-ok, or normalize-url. The description only states what the tool does, with no conditions, exclusions, or alternative tool references.

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