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

With no annotations, the description carries the behavioral disclosure burden. 'Body discarded' is a useful behavioral trait, but the description does not mention response format, network side effects, redirects, or error behavior, leaving a meaningful gap.

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 front-load the purpose and the key behavioral caveat with no filler. Every phrase 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 nine-parameter tool with no output schema and no annotations, one sentence is insufficient. The description does not explain how to choose among parameters or what the returned HTTP status looks like, and the sibling set contains similar URL/status tools that could have been differentiated.

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 schema coverage is 100%, the description does not map 'public library docs URL' to any of the nine optional parameters; the closest, url, is described as 'HTTPS URL to normalize or cite' rather than a status-check target. Since none of the params is required and several are discarded after unrelated checks, an agent cannot tell which parameter actually drives the call.

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 names a specific verb/resource pair: return the HTTP status of a public library docs URL, while explicitly noting the body is discarded. It distinguishes the tool by its scoped URL subject, though it does not name sibling tools like fetch-status or web-fetch.

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 'for a public library docs URL' gives a clear intended context and implies the tool should not be used for arbitrary URL fetching. It stops short of explicitly naming alternatives or when-not-to-use conditions, so it does not earn a 5.

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