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

With no annotations, the description carries the full burden, and it does disclose the two upstream sources and the cost of 2 credits, which is valuable context. However, it says nothing about return shape, latency, error conditions, or whether results are cached, so behavioral coverage remains partial.

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 clause with the purpose front-loaded and the cost appended, with no wasted words. But the brevity borders on under-specification given the tool's composite nature.

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?

For a composite data tool with no annotations and no output schema, the description omits key details: input format for 'domain', what the 'ownership change conclusion' output contains, and how segmentation/gaps are represented. It is too sparse to call the tool 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 0% for the single required parameter, and the description does not clarify what form 'domain' should take (apex domain, URL, IDN, subdomain handling). With one parameter and no schema documentation, the description should compensate but does not.

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?

States a specific resource (domain history) and the two data sources combined: RDAP registration events and Wayback segmentation/gap/ownership-change conclusions. The verb is implicit ('retrieve history'), but the composite nature distinguishes it from generic lookup tools. Slightly terse but clear.

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?

No guidance on when to use this versus a plain RDAP/Wayback lookup or any sibling tool, and no prerequisites or exclusions. The agent must infer the use case entirely from the name and resource description.

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