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

With no annotations, the description carries the full burden and does well: it discloses the price ($0.05 USDC), the 402-quote-then-pay flow, the requirement to reuse the same agent_ids on retry, and the REST bypass. It omits failure modes such as what happens on an invalid or expired payment_tx, but the core behavior is clear.

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 purpose and price, followed by the exact retry protocol. Every sentence earns its place.

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?

An output schema exists, so return values need not be explained. The description covers purpose, pricing, the two-step payment protocol, and an alternative auth path—everything needed to call a paid comparison 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 already 100%, so the baseline is 3. The description adds a genuine semantic constraint beyond the schema: payment_tx must be paired with the SAME agent_ids used in the quote call, which matters for correct invocation.

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 and resource: 'Compare trust scores across multiple agents — a head-to-head leaderboard.' The 'multiple agents' scope implicitly separates it from the single-agent trust tool, but it does not name a sibling explicitly, so a 4 rather than a 5.

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 concrete procedural guidance: call without payment_tx to get the 402 quote, then retry with the same agent_ids plus payment_tx, and notes the REST Bearer-key bypass. It does not say when to prefer this over mint_trust_score or mint_trust_history, so it stops short of full alternative routing.

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