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

No annotations exist, so the description carries the full burden. It usefully discloses deferred payment semantics ('Money is collected only after the returned URL is paid'), which is genuinely non-obvious. However it omits auth requirements, idempotency, and whether calling it reserves anything before payment.

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?

Two tight sentences with zero filler, and the deferred-payment behavior is front-loaded after the purpose. Nothing to trim.

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 payment-initiating tool with no annotations and no output schema, the description partially fills the gap by explaining the returned URL and when money moves. It still leaves returns, failure modes, and the second parameter unexplained.

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 50% schema description coverage and two parameters, the description adds no parameter meaning at all. amountUsd is documented in the schema (dollars, default 1, min 0.50) but 'description' is undocumented in both schema and description, and the description never compensates.

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?

States a specific verb+resource: 'Open a Stripe Checkout for Prior.' It distinguishes itself from siblings like confirm_payment by describing the checkout-creation step, though 'for Prior' adds little product context for an agent unfamiliar with the domain.

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?

Usage is implied rather than stated: the note that money is collected only after the returned URL is paid hints at a create-then-confirm flow with confirm_payment, but no explicit when-to-use or alternative-selection guidance is given.

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