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

With no annotations, the description carries the full burden and does disclose the economically important behavior: the user is charged the delivered price at pay_url via Stripe, the merchant fulfills directly, and late/wrong/missing items yield a refund. It omits idempotency/duplicate-order behavior and authentication expectations, which matter for a purchase tool.

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?

Dense and front-loaded: the resource, the customer shape, the payment model, and the confirmation requirement arrive in that order with no filler. The telegraphic "late, wrong or missing = refund" is terse but unambiguous.

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?

An output schema exists, so return values need not be explained, and the payment/refund model is covered. Still missing for a money-moving, nested-object tool: where product_id and variant_id come from (presumably search_products/get_product), quantity semantics, and what the agent field is for.

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 0% and the customer parameter is a nested object with additionalProperties, so the description's field-by-field spec (name, email, address1, address2?, city, state, zip, phone?) is valuable compensation. However, product_id, variant_id, quantity, and agent receive no meaning at all, so half the surface remains undocumented.

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?

"Order through Kaupia" states a specific verb and resource, and the body clarifies the flow (user pays at pay_url via Stripe, merchant fulfills). It does not, however, distinguish this tool from create_checkout or get_quote, which are the most likely confusable siblings.

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?

There is a concrete precondition ("Confirm item, address and total with the user before calling") and a hard constraint (US only), which is genuinely useful. But there is no explicit statement of when to use this versus create_checkout, get_quote, or order_status, leaving the selection decision to inference.

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