firestarter_cancel

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

Annotations already mark destructiveHint=true, and the description adds important behavioral context: the difference between voiding an authorization hold and refunding a captured payment. It does not contradict annotations and enhances understanding of financial side effects.

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 pack all necessary information without redundancy. The front-loaded first sentence names the action and resource, and the second sentence handles exceptions and alternatives.

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 simplicity of the tool (2 params, no output schema), the description is complete. It covers purpose, behavior, and edge-case handling, leaving no critical gaps for an AI agent to invoke it correctly.

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 coverage is 100% with per-parameter descriptions, so the schema does the heavy lifting. The description adds minimal semantic value ('active execution') but does not clarify the optional 'reason' parameter beyond its schema definition.

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 cancels an active execution and specifies the financial consequences (voiding holds vs refunding captures). It distinguishes itself from the related firestarter_return tool, making its purpose unambiguous.

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?

Explicitly gives a when-not-to-use condition ('already shipped can't be cancelled') and names the alternative tool (firestarter_return). This provides clear decision guidance beyond mere definition.

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