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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely non-obvious traits: a paid x402 micropayment on Base and a 1-25 address batch ceiling, which an agent must know before calling. It does not say what a hit/miss result looks like, so it stops short of 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 short sentences, front-loaded with the core capability, followed by the disclaimer and the payment/billing fact. No filler; every sentence carries actionable information.

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 a one-parameter read-only tool with no output schema, the description covers scope, input format, batch limits, cost, and legal caveat. The only gap is that the agent cannot anticipate the response shape (e.g., per-address match flags), which matters for a screening call.

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 0%, so the description carries the burden and does so: it reveals that the single 'address' string is actually 1-25 comma-separated addresses, explaining the 2500-character maxLength. It does not clarify whether mixed chains or duplicate addresses are accepted, capping it at 4.

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 (check) and resource (crypto wallet addresses) against a named dataset (OFAC SDN/Consolidated digital currency addresses). The wallet-address domain implicitly and clearly separates it from the sibling sanctions_screen_name, which handles names.

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?

Provides useful operational context (informational only, not legal advice; paid at $0.003 USDC on Base via x402) but never states when to choose this over sanctions_screen_name or get_licensed_entity. Usage is implied by the resource type rather than explained.

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