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

No annotations are provided, so the description must carry the full burden. It discloses a critical behavioral trait: the same-filesystem constraint and the failure mode, plus the recommended workaround. However, it does not mention overwrite behavior, error handling, or return values, which are relevant for a mutation tool. The description is transparent about its main limitation but leaves some behavior unspecified.

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 two sentences, front-loaded with the core purpose, followed by the critical constraint and workaround. Every word earns its place; no redundancy or fluff.

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's simplicity, the description is largely complete. It explains the operation, the key constraint, and the fallback. However, it omits details about what happens if the destination path already exists (e.g., overwrite vs. error) and does not specify the return value or any error format. With no output schema and no annotations, these gaps are minor but prevent a perfect score.

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 describes all three parameters (udid, remotePath, to). The description adds value by clarifying that remotePath and to must be on the same filesystem, and by implying remotePath is the source and to is the destination. This goes beyond the schema's basic descriptions, though it does not introduce new parameter details.

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 ('Move or rename') and resource ('file or directory') with a clear scope ('on the device'). It explicitly names its counterpart (ios_file_move) and differentiates it from other device_file_* siblings, making the tool's purpose unambiguous.

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 explicitly states when to use this tool versus alternatives: it warns that both paths must be on the same filesystem, and if moving across filesystems (e.g., /sdcard to /data), it will fail, recommending 'copy then delete instead'. This directly guides the agent to alternative tools (device_file_copy and device_file_delete) for the cross-filesystem case.

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