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

With no annotations, the description carries the full burden of behavioral disclosure. It states the method (HEAD) and minimal output, but does not explain the presence of nine seemingly unrelated parameters (ref, city, feed, etc.) or how they interact with the URL. This ambiguity could mislead an agent into thinking all parameters are relevant, whereas the description implies only 'url' matters.

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 no filler. It is maximally concise while conveying the essential operation.

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 nine parameters, no output schema, and no annotations, the description is inadequate. It does not define what 'status only' returns (HTTP status code, body, etc.), does not explain the purpose of the extraneous parameters, and omits error behavior or prerequisites. An agent cannot reliably invoke this tool beyond a simple HEAD request.

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%, but the parameter descriptions are cryptic (e.g., 'Git ref name; discarded after the shape check') and do not clarify their role relative to the stated purpose. The tool description adds no parameter guidance, so it fails to help the agent understand which of the nine optional parameters to populate for a typical URL status check.

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 verb (HEAD), resource (public URL), and output (status only), making the core purpose unambiguous. However, it does not differentiate this tool from siblings like browser-url-ok or playwright-url-ok, which also check URL status, leaving the agent to infer distinctions.

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 over alternatives. The description does not mention conditions, exclusions, or comparison with sibling tools, leaving the agent without routing criteria.

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