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

With no annotations provided, the description carries the disclosure burden. It explicitly discloses that the tool is free, does not pay, and behaves differently per tier: economy sorts by price, while verified filters to reliable APIs and ranks by a success/latency/price score. This is meaningful behavioral detail for an agent deciding whether to invoke it.

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?

The description is compact and front-loaded: it opens with 'FREE,' states the core action, and compresses tier behavior into two short clauses. The only minor redundancy is that 'FREE' and 'Does not pay' convey the same idea, but overall 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?

Given the tool's modest complexity, 100% schema coverage, and no output schema, the description covers the core behavior, tier semantics, and the critical no-payment constraint. It does not explicitly describe the return shape or contrast with sibling tools like search_bazaar or route_and_call, but the limit parameter already indicates ranked candidates are returned.

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?

The input schema covers all parameters, so the baseline is 3. The description adds value beyond the schema by explaining the verified tier's ranking components ('success/latency/price score') and clarifying that economy 'sorts by price.' It does not describe limit or max_price_usd, but the schema already documents those adequately.

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 states a specific action and resource: 'Search the x402 Bazaar for APIs matching a task and rank them.' It also distinguishes itself from execution/payment tools with 'Does not pay,' which separates quote_route from siblings like route_and_call or call_x402_api.

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 description provides clear context: use this tool to find and rank candidate APIs without paying. The tier explanation gives concrete selection guidance for economy versus verified. It does not explicitly name alternative tools or exclusion conditions, but 'Does not pay' and the ranking focus make the intended use apparent.

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