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

Adds substantial behavior beyond the annotations: never overwrites or merges an existing destination, does not follow symlinks, caps at 2 GB/10000 entries, returns a copyId immediately, and warns that an interrupted copy may leave a partial destination to inspect before retrying. That is exactly the kind of operational context annotations cannot express.

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?

Front-loads the core action and its safety profile, then layers limits, return behavior, and failure recovery in compact sentences. No sentence is redundant and nothing is buried.

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 no output schema, the description supplies the return contract (copyId plus polling via copy_status) and covers limits, symlink handling, and interrupted-copy recovery. Nothing an agent needs to invoke and follow up on this tool correctly is missing.

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 50% and from/to carry no schema descriptions, so the description does real work by clarifying the source/destination relationship and the non-overwrite rule. It reinforces workSessionId usage for polling, though it says nothing about deviceId, leaving one parameter unaddressed.

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?

States a specific verb and resource ('Copy a file or directory') plus the key scope qualifier 'keeping the source intact', which cleanly separates it from move_path. An agent can distinguish it from siblings without opening the schema.

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?

Explicitly routes the agent to copy_status with the same workSessionId for progress, and the 'source intact' phrasing implies when to prefer this over move_path. It does not state outright when-not-to-use or name move_path as the alternative, so it falls just short of a 5.

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