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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantial non-structured behavior: a $3 USDC x402 charge per call, a no-charge guarantee when too few sources answer, and the fact that with async=true the core source is checked before the job is queued and charged. It does not mention turnaround time, rate limits or what happens on a failed/webhook delivery, so it stops short of a 5.

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?

Front-loaded with the purpose, then the contents, then the cost/charging rules. Three dense sentences with no filler; the parentheticals carry real payment and async semantics rather than restating the name.

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?

No output schema exists, yet the description states the deliverable (20-question questionnaire with evidence, follow-up questions, PDF link), the payment model, and the async/webhook flow. Combined with the schema for pdf/async/webhook_url, an agent has enough to call this correctly.

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 75% (pdf and async documented, domain and webhook_url bare in the schema), so the description must add some meaning. It explains the async charging/queueing interaction in more operational detail than the schema's wording and confirms the PDF deliverable; webhook_url is left to the schema.

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+resource: an outside-in vendor security assessment producing a 20-question questionnaire with evidence, PDF and follow-ups. The enumerated coverage areas (email/DNS, TLS, subdomains, security.txt, trust centre, privacy policy, breach news, tech stack) make the scope concrete. However, it never differentiates itself from overlapping siblings such as report_privacy_policy, report_domain, domain_audit or certs, so an agent must infer the boundary.

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 context is implied by the description (run an outside-in security assessment of a vendor domain), and it notes costs and the async option. But there is no explicit when-to-use / when-not-to-use statement and no routing to alternative tools like report_privacy_policy or domain_audit that would cover part of the same ground.

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