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

Annotations already indicate this is a mutating, non-idempotent, non-destructive operation. The description adds valuable behavioral context: the operation is only available during a one-minute safety buffer and returns the campaign to a prior draft state. This goes beyond the structured data without contradicting it.

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 tight sentences, no filler. The core action and timing are front-loaded, followed by the concrete user trigger. Every sentence 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?

For a single-parameter tool with full schema coverage, annotations, and an output schema, the description provides all necessary context: what it does, when to use it, and what input is expected. Nothing critical is missing.

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 campaignId with a clear description ('Buffered campaign ID to return to its prior draft state'), and coverage is 100%. The tool description reinforces the meaning by tying the parameter to the one-minute safety buffer, helping the agent understand which campaign ID is relevant.

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 a specific action ('Undo a campaign send') with a precise scope ('during its one-minute safety buffer'), and the trigger is explicit: when the merchant asks to stop or undo a submitted campaign. This differentiates it from siblings like delete_campaign, update_campaign, or restore_campaign.

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 a clear when-to-use directive: immediately upon the merchant asking to stop or undo a submitted campaign, within the one-minute buffer. It does not explicitly state when not to use it or name alternative tools, but the context is strong enough for an agent to select it correctly.

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