Copy file or directory from host to Parallels guest

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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the mutation profile is known. The description adds valuable behavioral detail beyond the annotations: it creates parent directories if absent, uses direct stream execution, and supports multiple guest OSes. It does not elaborate on overwrite behavior, but the annotation coverage lowers the burden and the provided details are meaningful.

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 front-loaded with the core action, followed by two short contextual sentences, then a compact Args list. Every sentence adds useful information; there is no filler or repetition of schema-only trivia. The structure is easy to scan and parse.

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 tool has five parameters, three required, an output schema, and mutation annotations, the description covers all necessary invocation details: parameter meanings, OS compatibility, automatic directory creation, and timeout behavior. An agent can confidently call this tool without additional external information.

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 Args list in the description is essential. It explains all five parameters, including the distinction between host_path and guest_path, gives guest_path examples, and clarifies that user is optional and timeout_s defaults to 300. This fully compensates for the schema's lack of descriptions.

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 opens with a specific verb and resource: 'Stream a file or entire directory from the host into a guest path.' This clearly distinguishes the direction of copy from sibling vm_copy_from_guest, and the title reinforces the same host-to-guest operation. No ambiguity about what the tool does.

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 when to use the tool: whenever a file or directory needs to be transferred from host to guest. It adds context by stating it works across Windows, Linux, and macOS and that parent directories are created automatically. It does not explicitly name alternatives or exclusion conditions, but the context is clear enough for an agent to select it over vm_copy_from_guest.

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