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

With no annotations, the description must disclose behavior, but it only says 'HEAD a public URL and return status only,' implying no content retrieval. It does not mention side effects, authentication, or that most parameters are discarded (as hinted in the schema), leaving agents unaware of 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 a single, front-loaded sentence with zero redundancy. It is maximally concise, though this brevity contributes to its incompleteness.

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?

For a tool with 9 parameters and no output schema, this description is severely incomplete. It does not explain the purpose of the non-URL parameters, the meaning of 'status', or the return format. The schema descriptions partially compensate, but the tool description fails to tie everything together.

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 description coverage is 100%, so baseline is 3. The description adds no parameter-specific meaning, and it does not clarify how parameters like 'city' or 'json' relate to the HEAD operation, but it does not contradict the schema either.

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 (HEAD) and resource (public URL) but only mentions a single use case. The schema exposes nine parameters (city, json, zone, etc.) that are not referenced, making the actual scope ambiguous. It may be a multi-purpose status checker, but the description does not unify these elements.

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 siblings like web-fetch, browser-url-ok, or normalize-url. There are no exclusions or conditions that would help an agent select this tool appropriately.

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