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

With no annotations, the description carries the full disclosure burden and does well: it names the authoritative data source (Treasury's official OFAC list), the paid model ($0.002 per call over x402), accepted payment rails (USDC on Arc/Base/Solana, XNT on X1), the auth/signing requirement, and a legal scope caveat. It omits return shape, latency, and failure/caching behavior, which keeps it from 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?

Three sentences, front-loaded with what the tool returns, then the scope caveat, then cost and the call flow. Every sentence earns its place, though the pricing/payment sentence is dense enough that it reads as slightly overloaded.

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?

There is no output schema, so the description must hint at returns, and it does by naming the returned fields (entry, programs, list date, freeze status). Combined with full schema coverage on both parameters and explicit payment/auth behavior, an agent has what it needs to invoke correctly; only error and delay behavior are unaddressed.

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 baseline is 3, but the description goes beyond the schema by explaining the payment parameter's workflow semantics: that omitting it returns terms and that a signed payload passed back completes the purchase inside the same call. That is real added meaning over 'a signed x402 payment'.

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 (sanctions check) and resource (wallet on any chain), then enumerates exactly what is returned: OFAC SDN listing with entry/programs/list date plus USDC and USDT freeze status. Nothing among the siblings overlaps with this, so an agent can route unambiguously.

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 explicit procedural guidance for the two-step x402 flow ('call once without payment for the terms, sign them with your own wallet, call again with payment'), which is precisely when-to-call knowledge. It does not name an alternative tool or state when not to use this one, so it falls short of a full 5.

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