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

With no annotations, the description is the sole source of behavior. It mentions 'Body discarded' but does not explain side effects, network access, or how the tool handles the various input parameters. Very little is transparent about its actual runtime behavior.

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 (one sentence) but not well structured. It fails to front-load the essential information about which input to provide and what output to expect. Brevity here leads to ambiguity rather than clarity.

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 and no output schema, the description is grossly incomplete. It does not say what the tool returns (e.g., HTTP status code, boolean, hint), how to combine parameters, or what constitutes a valid library docs URL. An agent would be unable to use this tool correctly based solely on the description.

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?

The schema covers 100% of parameters, but the descriptions are generic and mostly say values are 'discarded after the shape check' or similar. The main parameter (likely 'url') is not explicitly identified, and the coherence between parameters and the stated purpose is missing.

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 'HTTP status for a public library docs URL' which gives a general goal, but it is vague and does not specify which parameter is the URL or how the many unrelated parameters (city, feed, host, etc.) fit in. The purpose is not clearly delineated from sibling 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 on when to use this tool versus alternatives like fetch-status, browser-url-ok, or normalize-url. The description offers no context for selection based on use case.

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