transfer_file

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

With no annotations provided, the description must carry the full behavioral burden. It states the operation (copy), supports bidirectional transfer via 'direction', and notes tilde expansion for computer_path. However, it does not disclose overwrite behavior, error handling, or whether directories are created, which are important for a file copy operation.

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 highly concise: a one-sentence purpose followed by a terse parameter list. It is front-loaded with the main function, and every line adds information without redundancy. There is no wasted wording.

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 tool with three required parameters and a straightforward operation, the description covers the essential usage: direction and both paths. It omits behavioral details like overwrite policies, but the presence of an output schema (though its content is unknown) may address return values. Given the simplicity and unrelated siblings, this is fairly complete, though a note on conflict handling would be beneficial.

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 coverage is 100%, so the schema already documents all parameters. The description adds value by explicitly listing the valid values for 'direction' (to_phone/from_phone) and clarifying that '~' is expanded in computer_path, which are not fully specified in the schema. This is a meaningful enhancement beyond the 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 clearly states the tool copies a file between a computer and a phone, with a specific verb ('copy') and resource ('file'). It is distinct from all sibling tools, none of which handle file transfer, so there is no ambiguity.

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 implicitly indicates usage by explaining the purpose and the parameters, but it does not explicitly mention when to use it versus alternatives. However, since no sibling tool serves the same function, the intended usage is clear from context alone.

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