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

With no annotations, the description carries the full transparency burden. It discloses the method (HEAD) and outcome (status), but the input schema includes many unrelated parameters (e.g., ref, city, zone) that are not explained in the description, leaving the actual behavior unclear and potentially misleading.

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 unnecessary words. It follows a clear verb-resource-result structure and is appropriately front-loaded.

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?

The tool lacks an output schema and the description only mentions 'status' without detailing the response format. More critically, the presence of nine unrelated parameters makes the tool's scope incomplete and confusing. It does not provide enough context for an agent to know which parameters are relevant or how they interact with the described behavior.

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 the schema covers all parameters with descriptions, the descriptions are misaligned with the tool's purpose. For example, 'ref' is described as a 'Git ref name' and 'city' as a 'City name for a public weather hint'—these have no apparent relation to HEADing a URL. The parameter descriptions do not add meaningful context and actively confuse rather than clarify.

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 action ('HEAD a public URL') and resource (URL) with an expected result ('return status'). It is specific and unambiguous, though it does not distinguish from sibling tools like browser-url-ok or web-fetch, which also check URL reachability.

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 such as browser-url-ok, playwright-url-ok, or web-fetch. The description implies usage for checking URL status but does not explicitly state conditions or exclusions.

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