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

No annotations are provided, so the description carries the full burden of explaining side effects, read-only behavior, or data access. It states the tool does not use WHOIS or ownership data, but does not disclose whether it performs network calls, modifies state, or has any rate limits.

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 extremely concise and front-loaded, stating the core action and scope in one short sentence. No filler or redundant wording is present.

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?

With nine parameters, no required fields, no output schema, and a description that only mentions hostname splitting, the description is not complete enough for an agent to understand which parameters are relevant, what the expected return value is, or how to handle the unrelated-looking parameters.

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?

Although schema descriptions cover 100% of parameters, most parameter descriptions are generic and appear unrelated to the stated purpose of splitting a hostname. There is no explanation of how parameters like city, feed, json, path, zone, or query relate to the operation, leaving an agent unable to determine which inputs are actually meaningful.

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 action 'split a hostname into labels' and includes a negative qualifier about WHOIS or ownership data, which helps define scope. However, it does not mention the many unrelated parameters in the schema, creating some ambiguity about the tool's true purpose.

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, and no mention of prerequisites or expected input formats. The negative qualifier is the only hint, but it does not clarify use cases or exclusions.

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