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

With no annotations provided, the description carries the full burden. It discloses that only a HEAD request is made and only status is returned, which is useful. However, it does not mention that many parameters are 'discarded' per the schema, nor does it describe side effects, rate limits, or error behavior. The gap between the description's narrow URL focus and the schema's broad parameter set is unexplained.

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 sentence, front-loaded with the core action and output. It is concise and waste-free, though its brevity contributes to the under-specification noted in other dimensions.

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 has 9 optional parameters, no output schema, and no annotations. The description only covers the URL scenario, leaving the agent without guidance on how to use the other parameters or when they apply. The complexity of the schema is not matched by the description, so an agent cannot confidently determine the correct invocation for non-URL tasks.

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 is individually documented. The description adds no extra meaning beyond the schema; it only reinforces the URL parameter's purpose. Since the schema already handles parameter semantics, a baseline of 3 is appropriate, though the description does not help disambiguate which parameters are relevant for the stated HEAD operation.

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 clear verb and resource ('HEAD a public URL and return status only'), but the schema exposes 9 parameters of which only 'url' matches that stated purpose. It does not explain why the other parameters (city, feed, json, path, zone, query, etc.) exist, creating ambiguity about the tool's actual scope. This undermines the clarity of its purpose.

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 given on when to use this tool versus sibling tools like browser-url-ok, playwright-url-ok, web-fetch, or domain-shape. The description does not mention alternatives, exclusions, or selection criteria, leaving the agent to guess.

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