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 mentions that WHOIS/ownership data is not retrieved, which is a positive detail, but it fails to disclose what happens with the other parameters (e.g., does it ignore them, validate them, or use them in some way?), nor does it describe the return value or any side effects. The mismatch between the narrow description and the diverse schema further reduces 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 that is front-loaded with the primary action and constraint. It is extremely concise with no filler or redundant wording, earning full marks for conciseness.

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 has 9 parameters, no required fields, no output schema, and no annotations, the description is severely incomplete. It does not explain what the tool does with the majority of the inputs, what the output format is, or how to use it correctly. An agent would have little idea of what results to expect or how to construct a valid call beyond the hostname parameter.

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%, so each parameter has a description, which normally sets a baseline of 3. However, the tool description does not explain how the parameters relate to the stated purpose of splitting a hostname; most parameters (ref, url, city, feed, json, path, zone, query) seem unrelated, and the description adds no meaning to them. The lack of alignment between the description and the parameter set makes the semantics confusing rather than clarified.

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 specific action (split a hostname into labels) and explicitly excludes WHOIS/ownership data, which gives a clear core purpose. However, it does not distinguish this tool from siblings like github-repo-shape or jira-key-shape, and the input schema exposes nine unrelated parameters (city, feed, json, etc.) that the description does not account for, creating ambiguity about the actual 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?

The description gives no guidance on when to use this tool versus any of the many siblings. It does not mention alternative tools, preconditions, or scenarios where this tool is preferable. An agent has to infer that this is for domain splitting only, but the broad schema suggests it might handle other shape checks, leaving usage unclear.

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