Start Parallels VM

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

The annotations already indicate a non-read-only, non-destructive operation, so the description does not need to restate that. It adds the 'registered VM' precondition, but it does not disclose whether starting is asynchronous, can fail if the VM is already running, or requires readiness checking.

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 eight words long, front-loaded with the action, and contains no filler. Every word contributes meaning.

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 one-parameter mutation tool with an output schema, this is largely complete: the action, target, and parameter format are clear. It would benefit from a note about asynchronous behavior or using vm_wait_ready, but that is not strictly required 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 input schema provides no description for the single 'vm' parameter, and coverage is 0%. The description compensates by specifying that 'vm' accepts either a name or a UUID, which is essential for correct invocation.

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 uses a specific verb ('Start'), a clear resource ('a registered VM'), and the accepted identifier types ('by name or UUID'). It is easily distinguishable from sibling tools like vm_stop, vm_suspend, and vm_list.

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?

Usage is implied by the tool's purpose: use it when the goal is to power on a VM. However, there is no explicit when/when-not guidance or mention of alternatives such as vm_status to check state or vm_wait_ready after starting.

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