key

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

No annotations are provided, so the description carries the full behavioral burden, and it discloses almost nothing. It does not mention that keys like HOME or BACK have significant side effects (leaving apps, navigating back), whether the call is blocking, what permissions or connection state are needed, or which device is targeted.

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?

A single short sentence, front-loaded with the verb and immediately followed by usable examples. It is efficiently sized for a simple tool, though its brevity contributes to the gaps noted elsewhere.

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?

An output schema exists so return values need not be described, but for a device-control mutation with no annotations the description is too thin. It omits the target-device parameter semantics, required connection/lease state, and the side effects of system keys.

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 0% and there are two required parameters. The description partially clarifies the 'name' field by giving example values, but does not indicate that it may be restricted to a fixed key set, and it offers nothing about 'phone' (presumably the target device).

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 gives a specific verb ('Press') and resource ('a key'), with concrete examples (BACK, HOME, ENTER, WAKEUP) that make the intent unambiguous. Among siblings like tap, type, and swipe, this reads as the discrete-key input method, though it never explicitly states that contrast.

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?

There is no guidance on when to use this tool versus tap, type, or swipe, nor any mention of prerequisites such as holding a device lease. The examples imply a domain of use but no conditions or exclusions are stated.

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