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

Beyond the readOnly/openWorld annotations, it discloses matching methodology (deterministic normalized-name and token matching), output semantics (CLEAR/REVIEW/HIT verdict, as_of and checked_at freshness), cost ($0.02 USDC on Base) and the full x402 payment handshake. That is exactly the behavioral context annotations cannot 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?

Front-loaded with purpose and list scope before the mechanics, pricing and payment flow. It is dense and the pricing/x402 sentence could be tightened, but each clause carries operational value and nothing is redundant filler.

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?

Despite having no output schema, the description specifies the return shape (verdict plus as_of/checked_at) and the delivery mechanism (x402 URL). An agent knows what it gets and how to pay, leaving no meaningful gap for a one-parameter tool.

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?

With a single parameter at 100% schema description coverage, the schema already documents 'name' fully. The description confirms it screens 'a person or company name' but adds no format, normalization, or edge-case guidance beyond the schema baseline.

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 (screen) and resource (person/company name) against named lists (OFAC SDN + Consolidated), with scope quantified (~40k names + aliases). It is clearly distinguishable from the sibling screen_sanctions_wallet, which screens a different identifier type.

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 check a payments, marketplace or KYC agent runs on every new counterparty" gives concrete usage context and the trigger (new counterparty). It does not explicitly state exclusions or when to prefer a sibling like check_carrier_authority, but the context is clear enough to route correctly.

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