get_pix

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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the description doesn't need to restate those. The description adds useful behavioral context: it clarifies that the agent never pays, and that the tool returns both copy-and-paste code and QR Code. However, it doesn't disclose side effects like whether the payment is marked as pending, whether repeated calls create multiple PIX charges, or any rate limits. The scope (billing:write) is mentioned in the description, which adds context beyond annotations.

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 concise and front-loaded with the main action. The parenthetical scope note is useful and doesn't waste words. The sentence about who pays is important behavioral context and earns its place. Slightly more structure could be added, but it's appropriately sized for a simple tool.

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?

For a tool with one parameter and no output schema, the description covers the main purpose and a key behavioral constraint (agent never pays). However, it doesn't describe the return format beyond 'copy-and-paste code and QR Code', doesn't mention error conditions (e.g., invalid order_id, order not found), and doesn't clarify whether the PIX code expires or is single-use. Given the billing context, these details could matter for an agent deciding whether to call the 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 description coverage is 0%, so the description must compensate for the undocumented order_id parameter. The description mentions 'the order's PIX payment' which implies order_id refers to the order for which payment is generated, but it doesn't explicitly explain the parameter format, required format, or any constraints. With only one parameter and a clear name, the meaning is inferable, but the description doesn't add explicit parameter-level detail beyond what the schema shows.

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 the tool's function: generating the order's PIX payment and returning the copy-and-paste code and QR Code. It identifies the specific resource (order) and the action (generates PIX payment). It doesn't explicitly differentiate from siblings, but the PIX payment context is unique among the listed sibling tools, so the purpose is clear enough.

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 implies usage context: it is for generating a PIX payment for an order, and it explicitly notes that the person pays, not the agent. However, it doesn't explicitly state when to use this tool versus alternatives, nor does it mention prerequisites like order status or payment state. The scope annotation (billing:write) provides some context but not explicit when-to-use guidance.

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