Start VM

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

Annotations already provide safety traits (idempotent, non-destructive, non-read-only). The description adds useful behavioral context beyond annotations: the nogui flag for headless start, the return confirmation message, and the fact that vmx_path must be absolute. No contradictions detected.

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 compact and well-organized: a one-sentence purpose, an Args list, and a Returns note. Every sentence carries essential information, with no filler or 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 start-VM tool, the description covers purpose, arguments, and return value. The absence of an output schema is mitigated by the explicit 'Confirmation message on success'. It could mention failure scenarios or prerequisites, but given the low complexity and strong schema/annotations, it is sufficiently complete.

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?

Schema description coverage is 100% for all three parameters, so the baseline is 3. The description repeats key parameter semantics (absolute path, headless behavior) but adds no new meaning beyond what the schema already provides. vm_password is only in the schema, not the description, which is fine given complete schema coverage.

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?

Description uses specific verb 'Start (power on)' and resource 'VMware Fusion virtual machine'. It clearly distinguishes from sibling operations like stop, suspend, reset, and snapshot management, leaving no ambiguity about the tool's function.

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 clearly implies use when a VM needs to be powered on, and the sibling list provides obvious alternatives (stop, suspend, reset). However, it doesn't explicitly state when not to use it or mention prerequisites (e.g., VMware Fusion running), so it stops short of a full 5.

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