Set Default Payment Method

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

Annotations declare idempotentHint=true and destructiveHint=false, and the description adds the functional consequence: the chosen method becomes the fallback for request_ride. No annotation contradiction exists. It does not detail persistence or failure behavior, but the annotations keep the burden low.

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?

One concise sentence states the action, the object, and the triggering condition, with no redundant words or restatement of the tool name.

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 one-parameter setter with idempotent, non-destructive annotations, the description covers the essential context. It could also mention what happens to a previously set default or what return value is expected, but these are not major gaps for such a simple operation.

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 100%: paymentMethodId is documented as 'Payment method ID' with minLength 1. The description adds no additional parameter semantics, so the baseline of 3 applies.

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 states a specific verb ('Choose'), a specific resource ('saved payment method'), and a precise effect ('used when request_ride omits a payment method ID'). This distinguishes it from list/add/remove payment-method siblings and clarifies default-setting behavior.

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?

It clearly indicates when the selection matters: whenever request_ride does not specify a paymentMethodId. It does not explicitly name sibling alternatives such as choose_payment_method, but the context makes the use case unambiguous.

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