list_saved_payment_methods

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

The description adds valuable behavioral context beyond the readOnlyHint annotation. It explains that results are paginated with instructions on using the 'after' parameter, recommends a default perPage value for comprehensiveness, and clarifies the nature of the data (saved payment methods for checkout vs. subscriptions). No contradictions with annotations exist.

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 well-structured and front-loaded with the core purpose, followed by usage notes and parameter guidance. Each sentence adds value, such as distinguishing from sibling tools and explaining pagination. It could be slightly more concise by integrating some details, but overall it avoids redundancy and is efficiently organized.

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?

Given the lack of an output schema and the tool's complexity (6 parameters, pagination), the description provides sufficient context for effective use. It covers key behavioral aspects like pagination, filtering, and sibling tool differentiation. However, it does not detail the structure of returned payment methods, which could be helpful since there's no output schema.

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?

With 100% schema description coverage, the input schema fully documents all parameters. The description adds minimal semantic context, such as implying that 'addressId' and 'supportsCheckout' are optional filters, but does not provide significant additional meaning beyond what the schema already specifies. This meets the baseline for high schema coverage.

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 purpose: 'list payment methods for a customer in Paddle' with the specific resource 'saved payment methods at checkout.' It distinguishes from sibling tools by explicitly contrasting with 'list_transactions' for subscription-related payment methods, making the scope unambiguous.

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 explicit guidance on when to use this tool versus alternatives: it specifies that this tool is for saved payment methods at checkout, not for subscription transactions, and directs users to 'list_transactions' for the latter. It also advises on default usage ('Use the maximum perPage by default') and when to apply filters.

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