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

Goes well beyond the annotations by disclosing data provenance (OFAC SDN list), refresh cadence (weekly), the exact response fields (sanctioned, currency, listed entity, programme), and the full cost model including the 5 free calls/day. Annotations already cover safety; the description adds the operational facts an agent needs before calling a paid tool.

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?

Three tight sentences: usage trigger first, then scope/data source, then return fields and pricing. No redundant restatement of the title, and the payment details are essential for an agent that must decide whether it can afford the call.

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, but the description enumerates the returned fields, and it covers cost, freshness, and supported chains. For a single-parameter read-only lookup, nothing an agent needs to invoke it correctly 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?

Only one parameter with 100% schema description coverage including an example address, so the schema carries the semantics. The description adds useful context about which chains/address formats are accepted but gives no per-parameter syntax or format rules beyond what the schema shows.

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 (checks/screens) and a specific resource (crypto wallet addresses) against a named source (US OFAC SDN list), and enumerates supported chains. The wallet/address scope distinguishes it from the name-based siblings like eu_sanctions_screen and pep_screen without ambiguity.

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?

Gives concrete triggering conditions: 'Use before sending crypto to an address, or when asked if a wallet is sanctioned.' Clear context for invocation, but no explicit when-not guidance or named alternative (e.g. eu_sanctions_batch for many addresses, or the x402_payee_check sibling).

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