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

With no annotations, the description carries the full burden of behavioral disclosure. It discloses that the body is discarded and only the status is returned, which is useful, but it omits any side effects, authentication, or rate limits. Moreover, the schema includes parameters like city, zone, json, and query that seem unrelated to the stated purpose, creating ambiguity and leaving the tool's behavior unclear for those inputs.

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 only two sentences with no filler. It front-loads the core purpose ('HTTP status') and adds the key behavioral note ('Body discarded') immediately. 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?

Given 9 parameters, no output schema, and no annotations, the description is insufficient. It does not explain how the parameters relate to the tool's purpose (e.g., which parameter is the URL?), nor does it describe the return format. An agent would struggle to decide which parameter to supply for a typical use case involving a library docs URL.

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 all parameters are described in the schema itself. The description does not add any parameter-specific meaning beyond what the schema provides, so the baseline score of 3 is appropriate.

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's purpose: it returns the HTTP status for a public library docs URL and discards the body. The verb 'HTTP status' and resource 'public library docs URL' are specific, but it does not explicitly differentiate from similar siblings like fetch-status or browser-url-ok, so it is a solid 4 rather than a 5.

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 description provides no guidance on when to use this tool versus alternatives. It does not mention any context, exclusions, or alternatives like fetch-status or browser-url-ok, leaving the agent to infer the scope on its own.

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