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

There are no annotations, so the description carries the full burden of behavioral disclosure. It reveals only the absence of WHOIS/ownership data and does not mention side effects, return behavior, input handling, or that the schema exposes many other parameters with 'discarded' semantics. The mismatch between the narrow description and the broad schema creates ambiguity.

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 with no filler. Every word contributes to the stated scope and the differentiation from ownership-oriented tools.

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?

The tool has 9 optional parameters, no required parameters, no annotations, and no output schema, yet the description addresses only one concept (hostname). It fails to explain what the tool returns, which parameters are actually used, and why the schema contains unrelated fields like city, feed, JSON, and query. This is inadequate for reliable invocation.

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 description coverage is 100%, so the baseline is 3 even without additional parameter detail in the tool description. The description adds some meaning for the host parameter by saying it is split into labels, but it does not explain the roles of the other eight parameters or how they relate to the described behavior.

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 uses a specific verb ('Split'), a clear resource ('hostname'), and a concrete outcome ('into labels'). The added phrase 'without WHOIS or ownership data' differentiates it from ownership-focused tools and from sibling shape tools like github-repo-shape or figma-url-shape.

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 implies usage by stating it splits hostnames and explicitly omits WHOIS/ownership data, so an agent can infer it is for shape-only checks. However, it does not name sibling alternatives or state when not to use it, leaving usage guidance mostly implicit.

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