google_activate_purchase_option

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

With no annotations, the description carries the full burden, and it does disclose the one important behavioral trait: this is a state-changing operation whose result is the option becoming purchasable. It says nothing about idempotency, what happens if already active, required permissions, or whether the change is reversible, which for an unannotated mutation is a real gap.

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?

One short, front-loaded sentence with zero filler; the verb and effect come first. It is arguably too terse for a mutation tool, but that is a completeness issue rather than a structural one.

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 three required parameters, no output schema and no annotations, a single sentence is barely sufficient. An agent can call it, but cannot tell from the definition whether an edit is required, whether activation is idempotent, or what state the option must be in beforehand.

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 description coverage is 100% and all three parameters are required and self-documented (packageName, productId, purchaseOptionId). The description adds no additional meaning such as ID formats or the relationship between productId and purchaseOptionId, so baseline 3 applies.

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 ('Activate') on a specific resource ('one-time product purchase option') and adds the effect ('becomes available for purchase'). It contrasts implicitly with the sibling google_deactivate_purchase_option and google_activate_subscription_base_plan through the resource naming, though it never names the alternatives.

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 only implied: the effect ('so it becomes available for purchase') signals you call this when a purchase option should be sellable, and the sibling deactivate tool implies the inverse. There is no explicit when-to-use, when-not-to-use, or stated prerequisite such as needing a committed edit.

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