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

With no annotations, the description carries the full burden of explaining side effects and behavior. It does not mention error handling, whether the tool performs network calls, or that most of the listed parameters appear to be ignored. The 'without WHOIS or ownership data' note is a small transparency step but insufficient.

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, front-loaded sentence that names the action and the key non-goal. It wastes no words and is easy to parse.

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 complex nine-parameter schema and no output schema, the description leaves out critical context. It does not specify the expected output format, which parameters are required or ignored, or how errors are reported. An agent cannot reliably call this tool based solely on the provided description.

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 every parameter has a schema description, most are unrelated to splitting a hostname and some are actively confusing (e.g., weather hints, RSS feeds, timezone names). The tool description does not clarify that only 'host' matters or explain what happens when multiple parameters are supplied. Schema coverage is high, but the semantic value is low.

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 a specific operation: split a hostname into labels. It also distinguishes itself by explicitly saying it does not provide WHOIS or ownership data. However, the presence of nine unrelated optional parameters creates ambiguity about which input is actually the hostname.

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 explicit guidance on when to use this tool versus alternatives. The phrase 'without WHOIS or ownership data' hints at what the tool does not do, but it does not name sibling tools or explain when domain-shape should be preferred.

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