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

Annotations cover safety (readOnly, idempotent, non-destructive), and the description goes well beyond them: it discloses the payment model (x402/MPP, $0.01 per call), that bad input is refused before any charge, and that the tool returns a paid request URL rather than the data itself. That payment/delivery behavior is not derivable from annotations or schema.

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?

Front-loads the purpose, then payment mechanics, then alternatives. Dense but every clause carries information; only minor looseness from packing the exception routing into a single trailing sentence.

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?

With no output schema, the description compensates by stating the return is the exact paid x402 request plus response schema and example, and that input validation happens before charging. An agent has everything needed to invoke the tool correctly.

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 both parameters (address with its 0x+40-hex pattern and request_key idempotency) are already documented in the schema. The description adds chain-scope context but nothing per-parameter beyond what the schema states, 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 verb (risk-label) and resource (EVM address) plus the exact rule set: OFAC SDN match, contract vs plain account, outgoing tx count with chain coverage. It explicitly distinguishes itself from token_risk and sanctions_screening_batch, so an agent can route without opening any schema.

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 an explicit when-to-use ('before paying it') and names two alternatives with the conditions that select them (ERC-20 -> token_risk; many addresses, OFAC-only -> sanctions_screening_batch). No inference required.

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