Pull a file from the device

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

Annotations declare readOnlyHint=false and destructiveHint=false, and the description adds genuinely new context: it refuses to overwrite an existing host file unless overwrite is true, and it explicitly confirms it writes to the host filesystem rather than being read-only. It does not describe failure modes or whether parent directories are created, but the overwrite guard-rail is real added value.

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?

Three short sentences, each carrying distinct information: what it does, its overwrite guard, and its filesystem-write nature. No filler or repetition.

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 and full parameter documentation, the description covers the essential behavior (direction, overwrite refusal, host-side writes) for a 4-parameter copy tool. Remaining gaps such as error handling and directory creation are minor for a tool whose annotations and schema carry the rest.

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%, with every parameter documented including the overwrite default and the relative-path resolution rule, so the baseline is 3. The description's mention of overwrite largely restates what the schema already says, adding little syntax or format detail beyond it.

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), resource (a file), and direction (from the device to the host machine), plus the underlying adb command. The direction alone distinguishes it from the sibling push_file without either schema being opened.

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 explicit device-to-host direction gives clear context for when this tool applies and implicitly excludes push_file's opposite direction. However, it never names the alternative or states a when-not condition, so it stops short of full routing guidance.

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