Select Rappi payment method

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

Annotations already declare readOnlyHint=false, destructiveHint=true, and idempotentHint=false. The description adds valuable context beyond these: the operation is gated by a global flag and user intent, guest tokens are rejected (an authentication restriction), and it explicitly states 'Does not charge' to clarify the side effect. This gives an agent important preconditions and avoids misinterpretation about charging.

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 extremely terse, with only four short statements: 'Gated payment write', the gating conditions, guest rejection, and 'Does not charge'. Each sentence carries distinct information, there is no fluff, and the most important classification is front-loaded. It is a model of conciseness.

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 three parameters (one required ID) and no output schema, the description leaves significant gaps: it never explains what payment_method_id refers to (e.g., that it should come from rappi_list_payment_methods), what a successful call returns, or whether it affects the current order/cart. The safety and gating info is helpful, but missing operational context makes it incomplete for correct invocation.

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 only 33% – only explicit_user_intent has a description. The description reinforces explicit_user_intent by naming it in the gating condition, but it adds no explanation for payment_method_id (what it should be or where to obtain it) or response_format (how it affects output). With low schema coverage, the description should compensate, but it doesn't.

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 labels the operation as a 'Gated payment write' and clarifies 'Does not charge', which combined with the title 'Select Rappi payment method' makes it clear the tool sets a payment method without charging. It implicitly distinguishes from read-only siblings like rappi_list_payment_methods by emphasizing it is a write operation, but it doesn't use an explicit verb like 'select' or 'set' in the description itself, relying on the title for that specificity.

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 usage constraints: requires RAPPI_ALLOW_MUTATIONS flag and explicit_user_intent=true, and rejects guest tokens. This tells an agent when it can be called, but it doesn't mention alternative tools or when not to use it (e.g., to view payment methods, use rappi_list_payment_methods; to finalize order, use rappi_place_order). The guidance is conditional but not comparative, leaving out any exclusions.

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