Execute a command in a Parallels guest

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

Annotations already flag destructiveHint=true and readOnlyHint=false, so the description does not need to restate those. It adds useful context about running inside the guest and the Windows desktop-user fallback, but it does not elaborate on side effects or failure behavior beyond what annotations convey.

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 a clear one-sentence purpose, followed by a concise Args list with defaults and examples. Every sentence adds useful information and there is no filler.

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 4-parameter tool with an output schema and destructive annotations, the description covers all invocation details: VM identifier, command vector, user handling, and timeout. It lacks usage-alternative guidance, but that is already scored separately; for calling the tool correctly it is nearly 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 0%, so the description carries the full burden for parameter meaning. It explains vm, command with concrete examples, the optional user with fallback behavior, and timeout_s with its default. This fully compensates for the bare schema.

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 ('Execute') and a specific resource ('an explicit argv vector inside the guest'), which clearly identifies the operation. The title reinforces this, and the description is distinct from sibling tools like vm_send_keys or file-transfer tools.

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 explains what the tool does but gives no guidance on when to prefer it over alternatives such as vm_send_keys or vm_copy_to_guest. There are no exclusions, prerequisites, or context about when this tool is the right choice.

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