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

The annotations already declare a read-only, idempotent, non-destructive, open-world operation. The description adds meaningful context beyond those annotations: the cost (0.02 USDC via x402 or 10 credits of a Factline API key), the daily free tier of 5 paid-tool calls, the possible outcomes (no_hits, review, block_review), and that the response includes list versions and a signed receipt. All of that would be hard to infer from the annotations alone.

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 dense but efficient: the trigger condition comes first, then the screening behavior, the return values, the inputs, and the pricing. Every sentence states a distinct fact. It's on the long side, but nothing is filler; the pricing and free-tier details are operationally important.

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's no output schema, so the description has to describe the return values, and it does: the no_hits, review and block_review outcomes, list versions, and a signed receipt. For a paid screening tool, the main gap is that it doesn't say how this differs from the closely related sibling tools, eu_sanctions_wallet and eu_sanctions_batch, when an agent has to choose.

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 33%, so the schema leaves gaps. The description partly fills them by naming the inputs (wallet, owner, optional owner_type, birth_year, country). But it doesn't explain expected formats, such as an EVM/bech32 address form or an ISO country code, and it never mentions the api_key parameter or its fl_live_ prefix, which the schema also documents. So it adds only moderate value beyond 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?

The description states a specific verb and resource: it screens a self-hosted wallet against OFAC-listed addresses, the claimed owner against sanctions and PEP lists, and the company register, then issues an evidence record. This is clear, but the description never mentions the sibling eu_sanctions_wallet. So the agent can't tell from the description alone which tool is the right one for a wallet-only screening.

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 gives a clear trigger: 'Use when a crypto service sends to or receives from a self-hosted wallet and must document its checks (EU AMLR, Travel Rule files)'. That tells the agent the context and the compliance purpose. But it gives no guidance on when NOT to use this tool, such as eu_sanctions_wallet or eu_sanctions_batch, and doesn't say what to do if the user only needs a quick screen.

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