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

With no annotations, the description carries the full burden of behavioral disclosure. It implies a read-only network query but does not mention RDAP vs whois fallback behavior, potential failure modes, rate limits, or whether the domain must be registered. This is sparse disclosure for a networked lookup tool.

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?

One short, front-loaded sentence conveys the resource and core output categories with no filler. Every word 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 simple single-parameter tool, the description lists the key output fields, which gives agents a basic expectation. However, with no output schema or annotations, the description could more thoroughly explain what the response looks like and what happens for invalid or unregistered domains.

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 coverage is 100% and the single parameter already includes a clear description with an example. The tool description adds 'Domain' context but no new semantic detail beyond the schema, so the baseline of 3 is 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?

The description identifies the resource (domain) and the data categories returned (status, dates, nameservers), which makes the tool's purpose fairly clear. However, it lacks a verb like 'retrieve' or 'query', reading more as a label than an instruction.

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 guidance on when to use this tool versus alternatives such as dns_lookup, validate_domain, or ssl_check. The description does not state exclusions, prerequisites, or fallback contexts, leaving selection to inference from the sibling names.

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