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

With no annotations, the description carries the full disclosure burden, and it only contributes the word 'real-time'. It says nothing about rate limits, authentication, whether the lookup is read-only (implied but not stated), or the common reality that WHOIS output is heavily redacted post-GDPR.

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?

A single front-loaded sentence with the verb, resource, and return categories, and no filler. Every clause 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?

For a one-parameter lookup with no annotations and no output schema, the description does list the main return fields, partially compensating for the missing output schema. However, it omits operational caveats an agent would want (redaction, rate limits, failure when no record exists).

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% and there is a single required 'domain' parameter with an example in the schema, so the schema already does the work. The description adds no format, TLD, or normalization guidance beyond what the schema provides, making the baseline 3 appropriate.

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 verb (lookup) and resource (WHOIS/RDAP for a domain) and enumerates the returned data categories, so the agent knows exactly what it retrieves. It does not distinguish itself from the sibling searchExpiredDomains, which is the nearest neighbor in intent.

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?

There is no when-to-use guidance, no mention of when to prefer this over searchExpiredDomains or other domain-related siblings, and no prerequisites stated. The agent must infer usage purely from the name and purpose line.

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