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

With no annotations present, the description carries the full disclosure burden but only reveals the absence of WHOIS/ownership enrichment. It does not disclose that inputs like 'ref', 'city', 'json', and 'path' are discarded after checks, nor does it describe output behavior. The one-sentence description is too thin to establish trust for a tool that accepts such a heterogeneous set of parameters.

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 filler, and the core constraint (no WHOIS/ownership) is placed early. It earns its place but sacrifices completeness for brevity.

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 exposes eight diverse parameters yet the description covers only one ('host'), and there is no output schema or annotations to fill the gap. An agent would not know this tool can also validate JSON, normalize URLs, or handle city/weather hints, making the description materially incomplete for correct 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?

The input schema provides descriptive text for all eight parameters (100% coverage), including the fact that several are 'discarded' after the check. The description adds nothing about parameters, so the baseline 3 applies; it neither compensates for gaps nor introduces ambiguity.

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 a clear resource 'hostname', and the qualifier 'without WHOIS or ownership data' distinguishes it from ownership-focused tools. It does not name sibling tools, so the differentiation is implicit rather than explicit, and the schema's additional params suggest the description under-scopes the tool's capabilities.

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 'without WHOIS or ownership data' phrasing hints at when not to use the tool (when ownership data is needed), but there is no explicit when-to-use statement or reference to alternatives such as github-repo-shape or figma-url-shape. An agent must infer applicability from the narrow hostname wording, ignoring the other accepted parameters.

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