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

Without annotations, the description must disclose side effects. It states 'return status only,' which is transparent about output, but it does not clarify whether the extra parameters are ignored, whether the HEAD request follows redirects, or any network/rate-limit consequences. The short description fails to fully inform the agent about the tool's actual 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 very brief—one sentence—which is concise, but it omits essential details about the parameter handling and tool scope. The structure is adequate for a simple tool, but the lack of clarity about the extra parameters makes it feel incomplete rather than efficiently succinct.

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 description is far too minimal. It does not explain the purpose of the 8 extraneous parameters, does not clarify that only 'url' is relevant, and provides no output schema or examples. The agent is left with a misleading impression that all parameters have meaningful roles, leading to potential misuse.

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?

The description does not explain any parameter, and the schema descriptions are wildly inconsistent (e.g., 'ref' says 'Git ref name; discarded after the shape check' and 'query' says 'Search text; discarded after the length check'), which are unrelated to a URL HEAD request. The agent cannot determine which parameter is actually used or how to pass the URL correctly.

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 action ('HEAD a public URL') and return behavior ('status only'), but the schema includes 8 unrelated parameters (ref, city, feed, host, json, path, zone, query) with nonsensical descriptions, creating ambiguity about the tool's true purpose and scope.

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 siblings like browser-url-ok, web-fetch, or normalize-url. There is no mention of prerequisites, limitations, or alternative scenarios, leaving the agent without direction for tool selection.

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