select_ab_test_winner

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

The description explicitly discloses the irreversible send to the remaining audience, adding context beyond the destructiveHint annotation. It specifies what the destructive action is ('real send to everyone who was held back') and states it cannot be undone, which is valuable behavioral transparency.

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, front-loaded with the action and resource, then a critical warning. Every word earns its place with no redundancy.

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?

The description covers the action, the audience affected, and the irreversible consequence. While it doesn't mention prerequisites or return values, the tool is simple and the annotations (destructiveHint, openWorldHint) supplement the context adequately.

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?

Input schema covers all parameters with descriptions (100% coverage), so baseline 3 applies. The description does not add additional parameter-level meaning beyond the schema.

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 states the tool's action: selecting the winning variant and sending to the remaining audience. It uses a specific verb ('select') and identifies the resource (A/B test winner), distinguishing it from sibling tools like create_ab_test or list_ab_tests.

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 context is clear: this is the final step after an A/B test concludes, sending to the held-back audience. It doesn't explicitly name alternatives or exclusions, but sibling tools show no competing select-winner tool, so the usage is unambiguous.

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