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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently states the HTTP method (HEAD) and that only the status is returned, but it omits any behavior related to the other 8 parameters—whether they trigger separate checks, are discarded, or require network access. The schema hints these are 'discarded' but the description adds no clarity on the overall 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 a single short sentence, which is concise, but it is grossly under-specified for a tool with 9 parameters and no output schema. The sentence does not earn its place because it omits critical information about the tool's full purpose and behavior; it is more a summary of one use case than a usable definition.

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 output schema, no annotations), the description is severely incomplete. It does not explain what happens with each parameter, what the response format is, whether the tool performs network requests for each, or how it relates to siblings. An agent cannot correctly invoke this tool for anything beyond the URL case based on the description alone.

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% — every parameter has a description, though terse. The tool description adds no additional parameter semantics beyond the schema. Since the schema already covers all parameters, the baseline of 3 is appropriate; the description does not compensate for the schema's brevity or clarify parameter interactions.

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 for one specific use case ('HEAD a public URL and return status only'), but the input schema reveals 9 distinct parameters (ref, city, feed, host, json, path, zone, query, url) that imply a much broader multi-purpose validation tool. The description fails to reflect this scope and is misleading about what the tool actually does beyond the URL case.

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 alternatives like browser-url-ok, normalize-url, or web-fetch. The description offers no context, no exclusions, and no mention of when other sibling tools would be more appropriate.

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