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

With no annotations, the description must carry the full burden of behavioral disclosure. It only states 'Body discarded,' which is a minor detail, and omits essential behavior such as redirect handling, timeouts, whether other parameters are actually used, or what 'HTTP status' means in edge cases (e.g., non-library URLs).

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 a single, concise sentence with no filler. It front-loads the primary action (HTTP status) and is appropriately brief, though it sacrifices necessary context in favor of brevity.

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 the tool's complexity (9 optional parameters, no annotations, no output schema), the description is severely incomplete. It does not explain what the tool actually accomplishes with the various parameters, when to use it, or what to expect in response. An agent would be unable to infer correct usage from this minimal text.

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%, so each parameter has a description, but the tool description does not clarify how these parameters relate to the stated purpose. For example, city and query are described as 'discarded after the call,' which directly contradicts the notion that the tool only checks a URL. The description fails to add meaning beyond the schema and even introduces confusion about parameter roles.

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 specific goal ('HTTP status for a public library docs URL') but fails to connect it to the 9-parameter schema, which includes unrelated fields like city, json, path, and query. The phrase 'public library docs URL' is ambiguous and does not clarify which parameters are expected or how the others are used, making the purpose misleading rather than precise.

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 versus its many siblings (e.g., web-fetch, fetch-status, browser-url-ok). The description provides no context, prerequisites, or exclusions, leaving the agent without criteria to select it correctly.

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