vm_create

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

Annotations already indicate a non-read-only, non-idempotent, non-destructive write operation. The description adds useful behavioral context beyond that: the VM starts powered off, includes one disk and one NIC, fails atomically if the datastore is not found, and returns a status string with the new VM name. It does not cover permission requirements or cleanup behavior, but it is solid given the annotation coverage.

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 front-loaded with the core purpose, then provides workflow guidance and failure behavior in just four sentences. Every sentence adds value, and no space is wasted repeating schema field details.

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?

Given the rich input schema, output schema, and annotations, the description supplies the missing behavioral and workflow context needed for correct use: what kind of VM is created, how to populate it, and what happens on datastore failure. It is complete enough for an agent to select and invoke the tool appropriately.

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%, and every parameter already has a clear description with defaults. The description adds little parameter-specific meaning beyond tying the hardware sizing parameters together ('one disk and one NIC'), so the schema carries the heavy lifting. This matches the baseline for full 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?

The description states a specific verb and resource ('Create a new empty VM') and clarifies the result: a powered-off VM with one disk and one NIC. It distinguishes itself from siblings like deploy_vm_from_ova and vm_clone by emphasizing that this creates an empty VM rather than a ready-to-run guest.

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?

It explicitly tells the agent when to use this tool versus alternatives: attach an ISO and power on, or use deploy_vm_from_ova or vm_clone for a ready-to-run guest. This gives clear decision guidance and names the sibling tools, leaving little to inference.

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