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, but it only enumerates accepted inputs. It says nothing about side effects (key events injected into the active app/window), whether a device must be specified, or error behavior for unrecognized names.

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 front-loaded sentence with the core action first and the accepted value formats after. No filler, though the trailing ellipsis leaves the name list open-ended.

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, and the primary input's format is explained. However, for a tool with 0% schema coverage and no annotations, the unexplained device parameter and absent routing guidance leave it only minimally complete.

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 parameters. The description does add real meaning for name_or_code (enumerated mobilerun-core names and the Android keycode number form), which the schema alone would not convey. It says nothing about the 'device' parameter, so it only half-compensates for the coverage gap.

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 (press) and resource (a keyboard/device key) and enumerates the accepted key names plus the Android keycode alternative. It does not, however, differentiate itself from the many sibling press tools (press, press_home, press_back, press_enter, volume_up, volume_down).

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 generic key tool versus the specialized siblings press_home, press_back, press_enter, volume_up or volume_down. No prerequisites or context are given; the agent must infer all routing decisions.

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