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

With no annotations, the description carries the behavioral disclosure burden. It discloses the $0.02 per-call cost, the data sources (RDAP, DNS, crt.sh), and the read-only intelligence-gathering nature. It omits minor operational details such as rate limits, timeout behavior, or output formatting, but the core behavior is transparent.

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?

Two sentences, front-loaded with cost and the bundle summary. Every clause adds information, and there is no filler or repetition.

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 description enumerates exactly what data the tool returns (RDAP fields, DNS record types, CT history), which is valuable given there is no output schema. It lacks only a concrete q example and error-condition notes, which keeps it from being fully complete.

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%, so the baseline is 3. The description adds domain context to the generic q parameter, helping infer that q represents the domain to investigate, but it does not specify the exact accepted format or keys (e.g. plain domain vs 'domain=...').

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 states a specific purpose: domain due-diligence covering RDAP registrar data, DNS records, and Certificate Transparency history, with an explicit use case ('vet a domain before trusting or linking to it'). This clearly distinguishes it from siblings like free_url_check, github_repo, or web_fetch.

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?

It gives an explicit when-to-use instruction: vet a domain before trusting or linking to it. However, it does not name alternatives or specify when not to use it, so it stops just short of full routing guidance.

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