get_pix

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

Adds substantial context beyond the annotations: human-in-the-loop payment, QR expiry window (up to 30 min) exposed via expires_at, and the non-idempotent behavior that re-calling yields a fresh QR — which corroborates idempotentHint=false. The required billing:write scope is also disclosed.

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 what the tool does and what it returns, followed by the safety framing and the expiry/re-call behavior. Nothing is redundant with structured fields.

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, yet the description names the returned artifacts (copy-and-paste code, QR code) and the expiry field, which is exactly what an agent needs to relay to the user. Mutation semantics and the human-payment constraint are covered.

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?

Only one parameter with 0% schema description coverage, so the description carries some burden. It refers to "the order's" PIX, tying order_id to an order, but adds no format or sourcing guidance (e.g. obtainable from create_order/list_orders). The parameter name is largely self-explanatory, so this is adequate rather than rich.

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+resource (generates the order's PIX payment) and names the exact return payload (copy-and-paste code and QR Code). An agent can distinguish this from create_order, get_order_status and redeem_code without opening any schema.

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?

Explains the operating context clearly: the human pays in their banking app and the agent never pays anything, plus the re-call semantics for an open order. It does not explicitly name a sibling alternative (e.g. get_order_status) for the case where the agent only wants status, which keeps it below 5.

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