Check payment and access

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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavior context: the 15-second polling constraint, the fact that webhook-granted access is confirmed only by fulfillmentStatus=fulfilled, and that paid/completed alone is insufficient. That is exactly the kind of status-semantics detail annotations cannot convey.

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?

Four short sentences, front-loaded with the action and resource, followed by the two decisive constraints and the return instruction. No sentence is filler.

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-value detail is unnecessary; the description still supplies the polling cadence, the access-granting status rule, and the id's origin. For a single-parameter read tool that is complete.

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 one parameter and 0% schema description coverage, the description adds useful meaning by saying the id is 'returned' and 'opaque', implying it comes from create_checkout. However, it does not explain the 64-character hex format enforced by the schema pattern, so it only partially compensates for the coverage gap.

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 (read) and resource (checkout) scoped to the connected account, and clarifies it takes the opaque id returned at creation. The read-vs-create distinction from the sibling create_checkout is obvious from the wording.

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?

Gives concrete operational guidance: poll no more often than every 15 seconds, treat only fulfillmentStatus=fulfilled as access granted, and return to the scoreboard task afterward. It does not explicitly name when to avoid calling it, but the conditions are clear enough to act on.

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