Merchant Trust ($0.05)

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

No annotations provided, so description carries full burden. Discloses cost ($0.05 USDC), output types (verdict + signals), and implied non-destructive nature (read-only lookup). Does not detail rate limits or authentication, but adequate for a simple tool.

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 concise sentence covering purpose, output elements, use case, and cost. Front-loaded with the key question. No redundancy.

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?

Given single parameter, no output schema, and simple tool, description fully explains outputs (verdict, signals) and usage context (before payment, cost). No gaps.

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?

Single parameter 'url' with schema description 'Store URL'. The tool description adds no further detail beyond the schema. Since schema coverage is 100%, baseline 3 is 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?

The description clearly asks 'Is this online store safe to buy from?' and specifies outputs: scam/fraud check, trust verdict (safe/caution/avoid), and store signals. It distinguishes from sibling tools like trust_check and crypto_market by targeting shopping/commerce agents before payment.

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?

States use case: 'counterparty trust for shopping & commerce agents before they pay'. Implicitly suggests when to use (before payment) but lacks explicit when-not-to-use or comparison with alternatives. Cost disclosure ($0.05) adds context.

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