cancel_service

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

The annotations only give destructiveHint=true, but the description elaborates that 'immediate' destroys the VM and data and requires confirm=hostname, while 'end_of_period' runs until the paid period ends. This adds concrete behavioral context beyond the annotation 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?

The description is a single, front-loaded sentence that efficiently conveys the action, mode options, consequences, and a required parameter. 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?

For a tool with three parameters, no output schema, and a destructive annotation, the description covers the core behavior and invocation requirements. It omits minor context like post-cancellation confirmation, but that is not essential for correct use.

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 describes all parameters (100% coverage), so the baseline is 3. The description adds value by explaining the behavioral difference between the two enum values for 'mode', but it does not provide new details for service_id or confirm beyond what the schema states.

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 states the verb 'Cancel' and the resource 'VPS', making the tool's primary action clear. It further distinguishes the two cancellation modes (end_of_period and immediate), which sets it apart from sibling tools like power_vps or reinstall_vps.

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 provides explicit guidance on when to use each mode: 'end_of_period' is the safe default, while 'immediate' is destructive and requires confirm. It does not mention alternative tools for similar actions (e.g., power off), but within this tool the mode-selection context is clear.

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