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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description still adds genuinely useful context: the $0.01 USDC price per successful call, the x402 payment rails (Base, Solana, Arc), and the fact that failed calls are not charged. It does not discuss rate limits or result completeness, but the payment/auth disclosure is exactly the kind of behavior the annotations cannot express.

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 the capability and followed by the cost/payment terms; nothing is filler. The intermediate clause listing page types is dense but earns its place by explaining where the data comes from.

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 single-parameter enrichment tool with read-only annotations and an output schema handling return values, the description covers what is fetched, where it is read from, and what it costs. Only minor gaps remain, such as failure modes beyond 'not charged' and coverage limits when no contacts are found.

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?

There is a single required parameter with 100% schema description coverage ('Website URL or domain, e.g. example.com'), so the baseline is 3. The phrase 'from a domain' reinforces that a bare domain is acceptable, but it adds no syntax, normalization, or redirect-handling detail beyond what the schema already provides.

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 precise verb-and-resource pair (company contact enrichment from a domain) and enumerates the returned artifacts: emails with same-domain flagging, phones, social profiles, description, tech stack. It also names the source pages crawled (home, contact, about, legal), which is enough for an agent to separate this from neighbors like domain, tech, or email_check without opening any schema.

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?

Usage is implied by 'from a domain' and the enrichment framing, so an agent can infer the input must be a company domain. However, there is no explicit when-to-use/when-not guidance and no named alternative (e.g., use tech for stack-only lookups, or domain for registration data), leaving routing to inference.

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