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

The description discloses that only the HTTP status is returned and that the body is discarded, which is helpful. It does not mention network side effects, errors, or any rate limiting, but with no annotations the key expectation is partially covered.

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 very short and front-loaded with the main purpose. It avoids fluff, but it is so terse that it omits important mapping between the purpose and the parameter schema.

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?

There is no output schema, no required parameter indication, no examples, and no explanation of how the many optional parameters relate to the documented purpose. An agent would struggle to know exactly what input to provide and what result to expect beyond a status code.

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 all 9 parameters, the tool description does not clarify which parameter holds the docs URL, and the schema mixes many unrelated optional fields with descriptions like 'discarded after the shape check.' The `url` description also says 'normalize or cite' rather than 'docs URL,' creating confusion.

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 the core operation—returning an HTTP status for a public library docs URL—and distinguishes this from general fetch tools via the 'public library docs' qualifier. However, it lacks an explicit verb and leaves 'library docs' somewhat ambiguous.

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 explicit guidance is given about when to use this tool versus siblings like fetch-status, browser-url-ok, or web-fetch. The intended context must be inferred from the tool name and the phrase 'public library docs URL'.

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