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

Annotations are absent, so the description carries the full burden. It discloses the report scope (four data categories) but says nothing about input requirements — notably that both schema params are optional and it is unclear whether host, domain, or both must be supplied — nor the output shape, failure modes, or that this performs live network lookups.

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 compact at roughly ten words with the substantive list (WHOIS, DNS, SSL, reputation) front-loaded. The opening 'DomainReport: Domain report —' is redundant and waste a few tokens, but the remaining content 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?

With no annotations, no output schema, and a sibling namespace containing many domain-related tools, this description under-specifies the tool. An agent cannot reliably determine required inputs (host vs domain), expected return format, or how this report differs from x402-domain-audit and x402-domain-intel, making correct invocation and selection uncertain.

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% (both host and domain have descriptions), so the baseline is 3. The tool description does not add meaning beyond the schema and fails to clarify the critical ambiguity: whether host and domain are alternatives, complements, or one takes precedence, especially since neither is required.

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 names the resource (domain) and enumerates the report's content areas (WHOIS, DNS, SSL, reputation), which is genuinely informative. However, it is self-referential ('Domain Report: Domain report —') and does nothing to distinguish this tool from overlapping siblings such as x402-domain-audit, x402-domain-intel, x402-whois, x402-ssl-check, and x402-dns-lookup, all of which cover overlapping ground.

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 is given on when to choose this combined report over the granular sibling tools (x402-whois, x402-ssl-check, x402-dns-lookup) or the other domain-level tools (x402-domain-audit, x402-domain-intel). An agent has no way to know whether a WHOIS-only request should route here or to x402-whois.

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