Copy a file or directory

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

The annotations declare a non-read, non-destructive, non-idempotent mutation, and the description adds real information beyond them: directories are copied recursively, and an existing destination is protected unless overwrite=true, so the agent knows a default call fails rather than silently destroying data. It does not cover permissions, symlink handling, or error/return behavior.

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?

Two short sentences with zero filler, front-loading the core action and following with the two behavioral constraints that actually change how an agent calls it.

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?

No output schema exists, and the description does not say what a successful copy returns (path, byte count, or nothing) or how failures are surfaced. Those are minor gaps for a three-parameter filesystem operation whose safety profile and recursion behavior are otherwise covered.

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 source, destination, and overwrite (including its default) are already fully documented in the schema. The description's mention of overwrite=true reinforces the safety semantics but adds no syntax or format detail beyond the structured fields, so the baseline 3 applies.

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 to another path") that an agent can easily distinguish from write_file or edit_file. It does not explicitly name the nearest alternative (move_path), so differentiation is inferred rather than stated.

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 implies when the tool applies (copying a file or a whole directory tree) and gives a concrete prerequisite for overwriting. But it never contrasts with move_path or write_file, so an agent must work out for itself when copying is preferable to moving.

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