Create Checkout Session

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

With no annotations, the description carries full burden. It only mentions behavior ('Creates... Returns a URL') but lacks details on side effects (e.g., idempotency, expiration, conditional requirements like line_items for certain modes). The schema provides param-level detail, but the description does not surface key aspects.

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 two sentences, minimal and focused, with no wasted text. It is front-loaded with the primary action and return value.

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 tool's complexity (12 parameters, nested objects, conditional requirements) and no output schema, the description is incomplete. It fails to mention critical constraints like line_items being required for payment/subscription modes, session expiration, or idempotency.

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%, so baseline is 3. The description adds no additional meaning beyond what the schema already provides for parameters. It does not highlight important parameter interactions (e.g., mode-dependent fields).

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 specifies the verb 'Create' and the resource 'Stripe Checkout session'. It distinguishes from sibling tools like create_payment_intent or create_subscription by naming the specific Stripe-hosted checkout flow.

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 for customer-facing payments by stating 'Returns a URL to redirect customers', but it does not explicitly state when to use this tool over alternatives such as create_payment_intent or create_subscription, nor does it provide exclusions.

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