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

Annotations already declare readOnlyHint=true, so the safety profile is covered by structured data. The description adds one genuine behavioral trait beyond annotations: the ordering guarantee ('latest first'), which tells the agent how to interpret the result sequence. It does not disclose pagination behavior or result volume, so it stops short of a 4.

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 sentences, no waste, front-loaded with the verb and resource before the endpoint reference. Every clause earns its place.

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?

With no output schema, the description does double duty by naming the action types returned plus the ordering, which is enough for an agent to call and interpret it. It could still mention pagination or whether the list can be empty on an unprocessed payment, so it is strong but not exhaustive.

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?

Only one parameter, and schema description coverage is 100% ('Payment id, e.g. pay_...'), so the schema fully documents the input. The description adds nothing about the id format or scope beyond what the schema already provides, making the baseline 3 correct.

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 ('List') and resource ('actions ... associated with a payment') and enumerates the action kinds returned (authorization, capture, refund, void). This clearly separates it from the sibling checkout_get_payment, which retrieves the payment itself rather than its action history.

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 by the resource description but there is no explicit when-to-use guidance or routing versus alternatives such as checkout_get_payment or checkout_list_payments. An agent must infer that this is the audit-trail companion to the payment detail call.

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