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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the agent knows this is a mutating, non-reversible operation. The description adds genuinely useful context that copies are recursive for directories, but does not disclose overwrite behavior at the destination or what happens on path conflicts — a meaningful gap for a destructive tool even with annotations present.

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 tight sentences, front-loaded with the core action and followed by the routing disambiguation. No filler; every clause carries information.

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 covers purpose, in-device scoping, recursion, and sibling routing, which is strong. It falls short of complete only by omitting destination-overwrite/conflict behavior expected of a destructive file operation.

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 100%, so the schema already documents udid, remotePath, and to. The description indicates the source may be a file or directory, which loosely maps to remotePath, but adds no path-format or overwrite semantics beyond the schema. Baseline 3 is appropriate.

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 (Copy) and resource (a file or directory on the device) and adds scope detail (recursive). It explicitly distinguishes itself from siblings by naming ios_file_copy as its counterpart and by clarifying that it copies within the device, not to/from the host.

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?

Provides explicit when-to-use/when-not guidance: 'Copies WITHIN the device — to move bytes to or from the host use device_file_pull / device_file_push.' The alternatives are named and the selecting condition is stated, leaving nothing to inference.

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