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

Annotations already declare read-only and open-world, and the description adds material context beyond them: pricing ($0.002 per successful call via x402 across Base/Solana/Arc, failed calls free) and a data-completeness limitation with the explicit warning that absence of a match proves nothing. That is exactly the kind of disclosure the annotation layer does not carry.

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?

One dense but front-loaded paragraph where each clause carries information (source, scope, filters, caveats, pricing). Slightly long, but nothing is filler; the data-completeness and pricing caveats are load-bearing.

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?

An output schema exists and annotations cover the safety profile, so the description only needs to explain source, scope, and limits -- which it does thoroughly, including the priced/x402 access model and the non-exhaustive-coverage warning an agent needs before relying on a negative result.

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 each of the three parameters is already documented. The description adds marginal meaning (currency codes like XBT/ETH/TRX, the Remarks-field source format) but no syntax or edge-case detail beyond the schema, 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 resource (OFAC SDN digital-currency addresses from the Remarks field), the scope (up to 200 entries), the fields returned, and the optional filters. No sibling in this large catalog covers sanctions screening, so the agent can identify it uniquely.

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?

Explains the two usage modes (filter by currency, or check one address) and includes an important caveat that a miss is not proof an address is clean and the list is not exhaustive per chain. It does not name an alternative tool or state when not to use it, but no plausible alternative exists among siblings.

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