discover_x402

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

With no annotations, the description carries the burden and does well: it discloses that results are read-only/no-cost, that prices are re-derived from the client's own registry, and that listing text is unverified seller-authored content — a real data-quality caveat. It stops short of describing rate limits, index freshness, or result cap 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?

Four short sentences, front-loaded with the core action, then scope, then return shape, then the routing caveat. No filler; each sentence adds a distinct fact.

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?

No output schema exists, and the description compensates by naming the returned fields (method, price, chain) and flagging the provenance caveat, while the schema itself covers offset/next_offset pagination. Still missing any note on empty-result or truncation behavior, but broadly complete for a read-only search tool.

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 100%, so every parameter (limit, query, offset, chain_id) is already documented in the schema, and the description adds little syntax detail. 'By subject' loosely maps to query and the return fields (method, price, chain) hint at chain_id's purpose, but this is baseline territory.

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') plus a precisely scoped resource ('x402-paid APIs by subject in the public x402 index — the Bazaar published by the CDP facilitator'). It is clearly distinguishable from the payment-oriented siblings quote_x402 and pay_x402.

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?

Explicitly tells the agent this tool does not spend money ('Nothing is paid') and routes to the correct next step ('follow up with quote_x402 or pay_x402'). The when-to-use (discovery) and when-not-to-use (anything involving payment) boundaries are both stated.

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