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

No annotations are present, so the description bears the full disclosure burden. The single sentence does say the operation excludes WHOIS/ownership data, which is useful, but it does not disclose return shape, error behavior, side effects, or whether the split is pure and local. For a tool with zero annotations, this is a significant gap.

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 compact sentence with no filler; the core operation and the key exclusion are both front-loaded. Every phrase earns its place.

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 no output schema, no annotations, and nine optional parameters, the description leaves important operational details unclear: which parameter is the actual hostname input, what the tool returns, and whether providing multiple parameters is meaningful. The definition is minimally understandable but not complete enough for an agent to invoke confidently.

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 though the tool description adds no parameter mapping. Each parameter is individually described, such as 'host: Public hostname', but the description does not explain why many unrelated fields appear or how they interact with the hostname split.

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') and resource ('hostname into labels'), and the negative 'without WHOIS or ownership data' sets clear boundaries. It is immediately distinguishable from sibling shape tools like github-repo-shape, figma-url-shape, or jira-key-shape, which target different entity types.

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 the tool is for hostname structuring when ownership/WHOIS data is not needed, but it never explicitly states when to prefer this over normalize-url, github-repo-shape, or other siblings. No when-not-to-use conditions or alternative tool names are provided.

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