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

With no annotations, the description carries the full burden. It discloses only that WHOIS/ownership is not included, but fails to describe the output format, how the nine parameters are handled, or any side effects. The behavior is largely opaque.

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 wasted words, so it is concise and front-loaded. However, it is so brief that it omits critical behavioral details, making it under-specified for an agent.

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 nine parameters, many of which seem irrelevant to hostname splitting (e.g., city, feed, json), the description does not explain their purpose or relationship. There is no output schema and no description of the return value, leaving the tool inadequately specified.

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?

The description adds no parameter-level information beyond what the schema already provides. Since schema coverage is 100%, the baseline of 3 applies, and the description does not enhance the understanding of any parameter.

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 tool splits a hostname into labels and explicitly excludes WHOIS/ownership data, which distinguishes it from other shape-checking tools. The action and resource are specific, so the purpose is unambiguous.

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 only provides a negative qualifier (without WHOIS/ownership) but does not name any alternative tools or state explicit conditions for when to use this tool over its siblings. There is no guidance on prerequisites or contexts.

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