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

No annotations are provided, so the description carries the full burden. It discloses useful behavioral facts: the upstream sources (RDAP, Cloudflare DoH, Certificate Transparency) and cost/auth requirements (Pro subscription or $0.005 per call). However, it omits rate limits, failure behavior, and whether returns are cached or verbose, leaving real gaps for a priced aggregation call.

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?

Three compact sentences with the core output front-loaded, then sources, then cost. No filler; every sentence carries distinct information.

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?

With no output schema and all parameters documented in the schema, the description covers purpose, data sources, and pricing adequately. Minor gap: it doesn't describe the shape of the aggregated response, but the essentials for invoking the tool are present.

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%, so the schema already documents all four parameters, their defaults, and the domain example. The description adds no parameter-level meaning beyond what the schema provides, so baseline 3 applies.

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 and resource: one call returns WHOIS, DNS, and SSL certificate data for any domain. This is concrete and distinguishes the tool from the unrelated siblings (memory.*, extract.*, gas.price). It stops short of naming alternatives, but none are obviously needed.

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 description implies when the tool is useful (aggregated domain intelligence in one call), but never states explicit when-to-use or when-not-to-use conditions, nor names an alternative. Pricing/subscription is mentioned, which hints at access conditions but is not usage guidance.

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