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 reveals the HEAD behavior and the 'status only' outcome, but is silent on what happens when other parameters are supplied (e.g., 'discarded after check' in the schema is not reflected in the description). The discrepancy between the described behavior and the parameter set seriously undermines transparency.

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 with no fluff, which is concise in word count, but it is severely under-specified for a tool with 9 parameters and 27 siblings. It does not 'earn its place' because it misrepresents the tool's true scope, making the brevity a liability rather than an asset.

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 complexity (9 parameters, no output schema, no annotations), the description is grossly incomplete. It does not explain how the diverse parameters affect behavior, what the return value actually includes (only 'status' for the URL case), or how the multiple 'shape check' scenarios are handled. The description is inadequate for an agent to correctly invoke the tool for any non-URL input.

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 each of the 9 parameters already has a description in the input schema. The tool description adds no additional semantic meaning beyond the schema. Since the schema is complete, the baseline 3 is appropriate; the description neither enhances nor contradicts the parameter documentation, though it fails to explain how parameters relate to each other.

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 it is misleading because the input schema includes 9 unrelated parameters (city, zone, query, json, path, etc.) that suggest a multi-purpose shape-check tool, not just URL status. It fails to distinguish from sibling tools like browser-url-ok or domain-shape, and the narrow description contradicts the breadth of parameters.

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. The description does not mention any exclusions, prerequisites, or conditions for selection among the 27 siblings. A tool with this many parameters needs explicit routing logic, which is completely absent.

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