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 does disclose meaningful commercial/authorization behavior — the tool is metered and requires a signed wallet with a 5-call free trial — which is genuinely useful context an agent cannot infer elsewhere. It says nothing about output shape, latency, partial-failure behavior when one of the four data sources is unavailable, or whether the call is read-only.

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 text is short and front-loaded, but it opens with 'Domain Report: Domain report —', restating the tool name twice before adding any information. The pricing line is compact and earns its place; the duplicated label does not.

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 two-parameter aggregation tool with no annotations and no output schema, the description establishes the scope of returned data reasonably well but leaves parameter selection entirely unexplained. An agent can guess what it will get back but not how to call it correctly if it only has a URL, or which of the two fields to prefer.

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 0% and neither of the two parameters (host, domain) has a description, so the description must compensate and does not. It never explains which parameter to supply, whether both are needed, or how host differs from domain (bare hostname vs. registrable domain), which is exactly the ambiguity an agent would trip on. Both parameters are also optional, and the description gives no hint about what happens if neither is provided.

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 a specific output artifact (a domain report) and enumerates its contents — WHOIS, DNS, SSL, and reputation — so an agent knows it is a multi-signal aggregate rather than a single lookup. It does not, however, distinguish itself from aggregate siblings such as x402-domain-intel, x402-domain-audit, or x402-domain-due-diligence, all of which sound nearly identical.

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 pick this over the numerous single-purpose siblings (x402-whois, x402-dns-all, x402-ssl-check) or the other domain-intelligence aggregates. The only usage-adjacent information is the commercial note about 5 free trial calls per signed wallet, which tells the agent about billing, not about task selection.

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