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

Annotations already cover read-only and open-world behavior. The description adds genuinely useful context beyond them: the tool is pay-per-call at $0.002 USDC, results are price-sorted ascending, and it draws from a specific directory. It stops short of describing pagination or error/failure behavior.

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?

A single, front-loaded sentence that leads with the verb and resource, then layers in source, ordering, return fields, and cost. Every clause carries information, though the trailing cost parenthetical is slightly awkwardly appended.

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 usefully enumerates the return fields (price, networks, 30-day payer counts) and discloses the per-call cost. The main gaps are undocumented limit semantics and the absence of any guidance distinguishing this from x402_check.

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 50%: network and max_price are documented in the schema, while q and limit are not. The description hints at q's semantics ('describe what you need') and at price-based ordering tied to max_price, but says nothing about the limit parameter or expected q format, so it only partially compensates.

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 (find) and resource (pay-per-call x402 services), names the source directory (Coinbase Bazaar), and specifies ordering (cheapest first). It is unambiguous on its own, but it never differentiates itself from the close sibling x402_check, so it falls short of 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?

The phrase 'describe what you need and get matching...' implies the usage pattern, and the cost note signals a paid call to weigh before invoking. However, there is no explicit when-to-use, when-not-to-use, or routing to alternatives such as x402_check or general search tools.

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