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

The description adds substantial behavioral detail beyond the annotations: the payment requires user browser approval due to EU PSD2, the agent cannot complete payment itself, and the session/reservation expires after 1 hour. This gives an agent a realistic model of the tool's side effects and limitations.

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 with no filler. It front-loads the core purpose, then packs the essential behavioral caveats and expiration policy into a compact, readable format.

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 checkout-creation tool with no output schema, the description adequately explains what is returned (Stripe URL and order publicId), what the agent should not do, and the 1-hour expiration. The main missing detail, explicit routing to get_order_status, is minor because the publicId-for-polling mention already signals the next step.

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 80%, so the schema already documents most parameters. The description adds no parameter-level detail beyond the schema, which is acceptable at this coverage level; locale remains undocumented in both schema and description.

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 action ('Create a checkout') and resource ('for one track'), and it distinguishes this tool from the read-oriented siblings by describing the Stripe hosted-payment URL and order publicId. An agent can tell this is the purchase-initiation tool without needing to inspect the schema.

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 gives clear operational context: the user must open the returned URL, approve payment in a browser, and the agent never completes payment. It implies polling with get_order_status via the publicId, but it does not explicitly name that 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.