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

Goes well beyond the annotations by disclosing pricing ($0.04 USDC via x402 on Base), the no-payment behavior (returns payment requirement, no charge), and the invalid-input billing exemption. It also frames the evidence basis ('public web evidence') and its limitations, which annotations alone cannot convey.

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 dense sentences, front-loaded with purpose and output contents before payment mechanics. Every clause carries information an agent needs and none is redundant with the schema.

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, the description supplies the return shape (summary, official-site facts, emails, mentions, evidence score, sources, limitations), the evidence basis, the exclusions, and the paid-call mechanics. Nothing material for correct invocation is missing.

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 schema already documents name, websiteUrl and the optional objective. The description only echoes that name and website are the inputs sent, without adding format or usage detail, 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 ('Company research and vendor due diligence: send a company name and official website, get a sourced profile') and enumerates the returned artifacts. The line 'Not legal identity, credit or registry data' cleanly separates it from registry-oriented siblings such as domain_rdap_lookup.

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?

Names concrete use cases (company lookup, supplier checks, KYB pre-screens) and explicit exclusions (not legal identity, credit or registry data). It does not name a specific alternative tool to use instead, which keeps it just below the top mark.

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