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

The description discloses key behavioral aspects: payment is completed externally by the buyer, the tool never charges or handles credentials, and for the module, the licence key is minted on payment and delivered via success page and email. This adds depth beyond the annotations, though it could have mentioned idempotence more explicitly given the idempotenceHint annotation.

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 and well-structured, covering the core purpose, the two offers, and the payment flow in a short paragraph. It front-loads the essential action and URL return, but the licensing details (Pro edition, volume discount) could be trimmed to reduce noise for a general agent.

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 provides sufficient context for a payment-related tool: it explains the external payment flow, licensing specifics, and the two offers. Without an output schema, it tells the agent that the URL is returned, which is the key return value. It could benefit from stating expected return format, but the essential details are present.

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?

The schema descriptions for offer_id and quantity are already quite clear (offer_id lists enum values with default, quantity explains licensing per installation). The description adds meaning by explaining what the offers are and how licensing works, particularly the edition (Pro) and volume discount, which helps an agent choose the right parameter values.

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: to create a Stripe Checkout Session and return its URL. It explicitly distinguishes the two offer types (readiness-sprint and module-pro) and clarifies that the tool does not charge a card or take payment credentials, removing ambiguity about its role.

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 explains when this tool is appropriate: for purchasing specific offers (readiness-sprint or module-pro). It contrasts with the sibling tool create_customer_portal_session, which is likely for managing existing subscriptions. However, it does not explicitly mention the sibling or state when not to use this tool.

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