create_customer_payment_method

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

With no annotations, the description carries full burden. It discloses that the tool is gateway-agnostic, requires a tokenized paymentMethodNonce, and does not accept raw card data. This adds important behavioral context beyond the schema, though it could mention idempotency or error cases.

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, containing two main sentences plus a list of required fields. It front-loads the purpose and key constraints. It could be slightly more structured, but it's efficient and readable.

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?

The description adequately explains the inputs and workflow, but it lacks information about the return value (e.g., created payment method ID) since there is no output schema. Given the complexity and lack of annotations, some behavioral details are missing.

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%, baseline 3. The description adds meaning by explaining that paymentMethodNonce is a single-use token from a payment integration and that billingAddress requires specific fields with an optional street2. This goes beyond the schema's field descriptions.

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 'Create a payment method for a customer,' specifying verb and resource. It distinguishes from sibling tools like get/update/delete/list_customer_payment_methods by focusing on creation, and it lists required fields, ensuring no ambiguity.

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 a clear workflow: obtain gateway client credential via get_client_token, produce paymentMethodNonce via payment integration, then call this tool. It also warns against sending raw card data. While it doesn't explicitly state when not to use it, the context is sufficient.

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