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

The phrase 'Body discarded' discloses a behavioral trait beyond the schema: the tool returns only HTTP status and discards the body. With no annotations present, the description carries the full burden, but it only covers this one behavior and omits other traits like error behavior, auth requirements, or side effects.

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 the core purpose front-loaded and no filler. Every word contributes value, especially the useful 'Body discarded' clarification.

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 7 parameters, no output schema, and no annotations, the description is far too thin. It explains only the URL/status behavior and leaves the agent unable to determine how or when to provide ref, city, json, path, feed, or host. Selection among the many parameters is left completely unexplained.

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 high: all 7 parameters have meaningful descriptions, so baseline 3 applies. The tool description itself adds no parameter-level meaning, and its single-purpose framing (public library docs URL) potentially obscures the purpose of unrelated params like city and json, though it doesn't directly contradict them.

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 and resource ('HTTP status' for 'a public library docs URL'), which clearly states the core action. However, it doesn't differentiate the tool from sibling tools such as fetch-status or browser-url-ok, and the mention of 'public library docs' conflicts with the schema's generic parameters like city and json, reducing clarity.

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?

There is no guidance on when to use this tool instead of siblings like fetch-status, normalize-url, or web-fetch. The description does not mention any conditions, exclusions, or situations that would direct an agent to choose this tool over alternatives.

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