List Virtual Machines

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

Annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds valuable context by deliberately noting that device details, including VNC display passwords, are omitted—an important behavior for security and expectation setting.

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?

Two sentences front-load the action and provide a complete summary of included fields and the deliberate omission. No redundant words or repetition of schema information.

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?

With an output schema present and a read-only list operation, the description covers the key return fields and notes the omitted sensitive details. This is sufficient for an agent to decide to call the tool and interpret results.

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 (response_format) is fully described in the schema with enum values and default; description coverage is 100%. The tool description adds no extra parameter meaning, matching the baseline of 3 for high 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 clearly states the tool lists virtual machines and enumerates the specific attributes returned (run state, autostart, vCPU/memory, bootloader, device summary). This distinguishes it from sibling list_* tools that target other resources like pools or disks.

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 context is implied by the tool name and description; it is evident this is for enumerating VMs. However, there is no explicit when-to-use/when-not-to-use guidance or mention of alternatives for obtaining full device details, which would improve clarity.

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