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

The description does not disclose any behavioral details such as return format, error handling, side effects, or whether it is read-only. With no annotations, the agent has no idea what to expect after invocation.

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 only one sentence and lacks structure. It is concise but not informative, and the phrase 'without WHOIS or data' is ambiguous. The layout of parameters is standard but the description itself is poorly organized.

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 multiple parameters and the presence of sibling tools, the description is far from complete. It does not explain the relationship between parameters, expected input formats, or which sibling tools to use as alternatives. The tool appears overloaded without sufficient context.

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?

Each parameter has a brief description (url, host, json, zone), but these descriptions do not explain how they relate to the stated purpose of splitting a hostname. The semantics are inconsistent and lack context for how the parameters are supposed to be used together or separately.

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 it splits a hostname into labels, but the parameters include url, json, zone, which do not align with that purpose. It is unclear which parameter is the primary input or whether the tool handles multiple unrelated tasks.

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 vs. siblings like normalize-url, validate-json, or timezone. No explicit conditions or examples are provided to distinguish appropriate use cases.

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