Start virtual machine

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

Annotations already mark the operation as not read-only and not destructive. The description adds useful behavioral context by noting idempotency: 'If the virtual machine is already running, the request will still be processed without any effect.' This goes beyond the structured annotations.

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 concise and well-structured: a clear action sentence, an important idempotency clarification, and a direct usage instruction. Every sentence earns its place without 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 simple one-parameter start operation with no output schema, the description covers the purpose, the target state ('stopped VPS instances'), and the already-running edge case. Nothing essential is missing for correct invocation.

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 only parameter, virtualMachineId, is fully described in the schema as 'Virtual Machine ID' (100% schema coverage). The description does not add further parameter-level meaning, so a baseline score of 3 is appropriate.

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 action and resource: 'Start a specified virtual machine' and 'power on stopped VPS instances.' It does not explicitly name sibling tools like VPS_stopVirtualMachineV1 or VPS_restartVirtualMachineV1, so sibling differentiation is implied rather than explicit.

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 a clear usage condition: 'Use this endpoint to power on stopped VPS instances.' It does not mention alternatives or exclusions, but the context is sufficient for deciding when to invoke it.

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