Check an address before sending it funds (deep tier, $0.50)

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

Goes well beyond the annotations by disclosing the full cost model: always $0.50 USDC on Base via x402, paid from VERDIX_PRIVATE_KEY, refused up front if above VERDIX_MAX_PRICE_USD, and 503 responses are not charged. It also decodes the 'danger'/'caution' verdicts into actionable conditions.

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 action, tier and price, and the return-shape summary is dense but useful. The clause 'this tier additionally runs the same checks as standard today' is mildly confusing and could be tightened, costing a point.

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 fully documents the return payload (verdict, risk_score, reasons, checked, tier, price_usd, as_of) and its interpretation. Combined with the payment and tier semantics, an agent has everything needed to call it 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 description coverage is 100% for the single 'address' parameter, so the schema already carries the semantics. The description adds no format or syntax detail beyond what the schema provides, making the baseline 3 appropriate.

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 ('an EVM address on Base'), and pins itself to a distinct tier. It explicitly tells the agent that check_address_risk with tier="deep" is the equivalent, so the sibling relationship is unambiguous.

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 explicit when-to-use guidance ('pick it for high-value or first-time transfers, not for extra checks') and names the alternative that avoids the dedicated tool. Both the selecting condition and the exclusion are stated.

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