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

Annotations already declare readOnly, idempotent and openWorld, so safety is covered. The description adds genuinely non-obvious behavior: per-call pricing ($0.02 USDC on Base, x402) and the fact that a payment-signature-free call returns x402 payment requirements rather than results. It stops short of describing match-score semantics or rate limits.

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 compliance purpose and when-to-use condition are front-loaded, followed by the payment mechanics and a sample pointer. Every sentence carries information, though the bracketed category tag and price/sample metadata make it slightly denser than a pure task 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?

For an 8-parameter tool with no output schema, the description covers the otherwise invisible x402 payment flow and the conditional return value, which is the highest-risk unknown. Screening semantics and result shape are largely covered by the rich schema, leaving only minor gaps.

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 description coverage is 100%, so every parameter including dob, country, min_score, lists and payment_signature is already documented in the schema with defaults and ranges. The description adds no parameter-level meaning beyond that, so the 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 (screen) and resource (customer/supplier/payee against official sanctions lists) with the compliance framing. It does not distinguish itself from close siblings like batch_sanctions_screen, screen_pep or counterparty_due_diligence, so the agent must infer the boundary from the name alone.

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?

"Use when one party must be cleared before money or goods move" gives a clear triggering condition and the onboarding/contracting/paying context. It offers no explicit exclusions or named alternatives (e.g. batch vs. single screening), so routing between siblings is left to inference.

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