start_vm

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

No annotations are provided, and the description gives zero behavioral context. For a mutating operation, it should disclose effects like whether starting an already-running VM fails or is a no-op, any required permissions, or side effects. The bare statement 'Start a VM' fails to carry the burden that annotations usually bear.

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?

While the description is short, it is under-specified rather than concise. It restates the tool name and does not provide any useful context. The single sentence does not 'earn its place' because it adds no information beyond the name.

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?

The description lacks critical context for correct invocation: when to use this tool, what happens on success or failure, whether it's idempotent, and any prerequisites. The schema covers parameters, but with no annotations or output schema, the description fails to provide a complete picture for a mutating operation.

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 describes both required parameters (node and vmid) with clear types and descriptions, achieving 100% coverage. The description adds no additional meaning to the parameters, so the baseline score of 3 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 'Start a VM' literally restates the tool name 'start_vm' in natural language, making it a tautology. While it does name an action and resource, it adds no specificity beyond the name itself. The differentiation from sibling tools like stop_vm or restart_vm comes only from the verb, which is already evident in the tool name.

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 no guidance on when to use this tool versus alternatives such as start_container, shutdown_vm, or restart_vm. It does not mention prerequisites, preconditions (e.g., VM must be in a stopped state), or any conditions that should be checked before starting.

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