Stop virtual machine

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

Beyond the annotations, it discloses idempotent behavior for already-stopped VMs, clarifies that this is a compute-only power state change with no billing impact, and points to auto-renewal disabling as the way to stop future charges. This adds meaningful operational context beyond the bare destructive/read-only flags.

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 front-loaded with the core action, then adds only valuable caveats: idempotence, billing independence, and the alternative for stopping charges. Every sentence earns its place without unnecessary padding.

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 power-state operation with annotations covering mutation and destructiveness, the description fully covers the relevant operational context: what it does, what happens if already stopped, billing implications, and how to avoid future charges. Nothing needed to call it correctly 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 fully documents virtualMachineId as 'Virtual Machine ID' with integer type at 100% coverage. The description adds no additional parameter semantics, so the baseline score for high schema coverage 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?

The description explicitly states 'Stop a specified virtual machine' and 'Use this endpoint to power off running VPS instances,' clearly identifying the action, resource, and intended effect. This distinguishes it from sibling operations like start or restart without ambiguity.

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 clear usage context: use it to power off running VPS instances. It also notes that stopping an already-stopped machine has no effect, and clarifies that this is not a billing action. It does not explicitly name the start/restart alternatives, but the intended condition is clear enough.

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