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

With no annotations, the description carries the full burden and does add one meaningful behavior: the body is discarded, so only the status matters. It does not disclose request method, redirect/error behavior, authentication needs, or what counts as a valid library docs URL, leaving notable gaps.

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 two short sentences with no filler. The core operation and the key caveat are front-loaded, and every word earns its place.

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?

For a tool with nine optional parameters, no annotations, and no output schema, this description is too thin. An agent cannot tell which input to provide, which URL shapes are valid, or how to interpret the returned status, making reliable invocation unlikely.

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 coverage is 100%, but the description does not explain which of the nine optional parameters to use, and several parameters (city, json, zone, query) seem unrelated to the stated purpose. The schema's url description says 'normalize or cite' rather than 'fetch status', so the structured parameter info is of limited help and even somewhat conflicting.

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 concrete operation—return the HTTP status of a public library docs URL—and notes that the body is discarded, so the agent knows what kind of result to expect. However, it does not differentiate this from sibling tools like fetch-status or web-fetch, which also deal with URLs and HTTP behavior.

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 phrase 'public library docs URL' gives a narrow intended context, and 'body discarded' implies it should not be used when the response body is needed. But no alternatives are named and there is no explicit when-to-use versus when-not-to-use guidance, so usage remains mostly implied.

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