Acknowledge Subscription Purchase

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

With no annotations provided, the description carries the full burden and adds valuable behavioral context: Google automatically refunds and revokes unacknowledged purchases within three days. This tells the agent that the call is operationally mandatory and time-sensitive, though it does not mention authentication, idempotency, or side effects beyond acknowledging.

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 compact, front-loaded with the action, and the second sentence provides a concrete reason the call matters. There is no redundant or filler content.

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?

Given the full input schema, output schema, and the simple parameter list, the description is largely complete. It covers the key operational context and urgency, though it could be more complete by explicitly mentioning the similar acknowledge_product_purchase alternative or any required prior steps such as obtaining the purchase_token.

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?

The schema already documents all four parameters with 100% coverage, including an example for package_name and descriptions for each field. The description adds no additional parameter-level detail, which is acceptable since schema coverage is complete.

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 identifies the action (acknowledge) and resource (subscription purchase), so an agent can tell what the tool is for. However, it does not explicitly differentiate from the similar sibling acknowledge_product_purchase, instead relying on the resource name to make that distinction.

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 context: this must run for every new subscription purchase to prevent automatic refund and revocation. It does not mention alternatives or exclusions, but the urgency and required use are explicit enough for most call scenarios.

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