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

Annotations already cover read-only, idempotent, and open-world semantics. The description adds that it produces a signed XDR-1 receipt and lists the screening criteria (e.g., '<30d = scam'), which are useful behaviors beyond the annotations. It does not explicitly state failure handling, but this is a minor gap given the annotations and output schema.

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 concise and front-loaded with the primary purpose. It uses a short sentence plus a list of checks and an output note, with no redundant filler. The title also reinforces the usage context without repeating the full description.

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?

Given the tool has 8 optional parameters and an output schema, the description is sufficiently complete: it specifies inputs (implicitly via check list), the checks performed, and the output (signed receipt). It does not detail the receipt contents, but that is covered by the output schema. Overall, an agent can call this tool correctly based on the description alone.

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?

The schema covers 100% of parameters with descriptions, so the baseline is 3. The tool description enhances parameter understanding by explaining how parameters are used in the checks (e.g., vendor_domain for domain age and disposable email detection, declared_country for BEC mismatches), adding meaning beyond the individual field descriptions.

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 explicitly states the tool's core function: verifying counterparties before disbursements, and enumerates the specific checks (IBAN, domain age, email domains, CRN/LEI, BEC mismatches). This clearly differentiates it from sibling single-purpose checkers like iban_check or lei_check by positioning it as a comprehensive due-diligence guard.

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?

The description signals mandatory usage ('MANDATORY', 'Check Before You Send') for pre-disbursement scenarios, implying it should be used before releasing payments. However, it does not explicitly name alternatives or contrast with the individual check tools, though the title and context make the intended use reasonably clear.

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