press_keySend a HID key code to the iOS Simulator to trigger a key press such as Return, Tab, Space, or letters, enabling keyboard input and navigation.
Press a single HID key code. Common codes: 40 = Return/Enter, 42 = Backspace/Delete, 43 = Tab, 44 = Space, 41 = Escape, 4-29 = a-z, 30-38 = 1-9, 39 = 0.
| Name | Required | Description | Default |
|---|---|---|---|
| keyCode | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden. It discloses that it presses a single HID key code, which implies a low-level input action. It doesn't mention whether the key press is a tap (down+up) or a hold, or whether it requires a device to be connected. However, the description is honest about what it does, and the key code list adds useful context. It doesn't contradict any annotations (none exist).
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?
The description is two sentences: the first states the action, the second provides a compact, useful reference. No wasted words. The key code list is front-loaded and easy to scan.
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?
For a simple one-parameter tool, the description is quite complete. It explains the parameter and gives common values. It doesn't mention return values (no output schema), but for a key press tool, the return is likely trivial. It could mention whether the key press is a tap or hold, but that's a minor gap. The sibling list shows this is part of a device control suite, and the description fits that context.
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 0%, so the description must compensate. It explains the keyCode parameter by providing a mapping of common codes to keys, which adds significant meaning beyond the bare integer type. It doesn't explain the full range or all possible codes, but it gives enough for common use cases. This is strong compensation for a single parameter.
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 clearly states the tool's function: 'Press a single HID key code.' It specifies the resource (HID key code) and the action (press), and the title reinforces it. It distinguishes from siblings like type_text (which types text) and tap (which touches the screen) by focusing on HID key codes.
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 provides a list of common key codes, which implicitly tells the agent when to use this tool (e.g., for Enter, Backspace, Tab, Space, Escape, letters, numbers). It doesn't explicitly state when not to use it or name alternatives, but the context of siblings like type_text and tap makes the usage context clear. The key code list is practical guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.