Mobile Automator MCP Server

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Boot Simulator

boot_simulator

Idempotent

Boot an iOS simulator by UDID and wait until it reaches the Booted state. Idempotent: returns ready status if already running.

Instructions

Boot an iOS simulator by UDID and wait for it to be fully ready. Idempotent — returns alreadyBooted=true if already running. Opens Simulator.app by default. Android emulator booting is not yet supported (start it manually).

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "platform": "<platform>",
      "deviceUdid": "<deviceUdid>"
    },
    "name": "boot_simulator"
  }
}

Input Schema

Name	Required	Description
`platform`	Yes	Target mobile platform (Android booting is not yet supported)
`timeoutMs`	No	Max wait in ms for the device to reach Booted state. Default: 120000.
`deviceUdid`	Yes	Simulator UDID to boot (from list_devices)
`openSimulatorApp`	No	iOS only: open Simulator.app to surface the UI. Default: true.

Output Schema

Name	Required	Description
`state`	Yes	Device state after the boot attempt
`output`	Yes
`passed`	Yes	Whether the device reached Booted state
`platform`	Yes
`deviceUdid`	Yes
`durationMs`	Yes
`alreadyBooted`	Yes	True if the device was already Booted before the call

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 28, 2026

TDQS

A4.2/5.0

Behavior3/5

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

Annotations already declare idempotentHint=true, destructiveHint=false, and openWorldHint=true. The description adds that it opens Simulator.app and returns alreadyBooted=true on re-boot, but does not elaborate on other side effects or resource usage. With annotations covering core traits, the description adds moderate value.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences pack all essential information: action, idempotency, Android limitation, and default behavior. Perfectly front-loaded with no waste.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present (context signals), the description does not need to detail return values. It covers core functionality, idempotency, platform restriction, and defaults. Minor gaps exist (e.g., meaning of 'fully ready'), but overall adequate for a boot tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, but the description adds meaningful context beyond the schema: it notes 'from list_devices' for deviceUdid, clarifies the Android limitation for platform, and states the default for openSimulatorApp. This extra guidance improves parameter understanding.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool boots an iOS simulator by UDID, waits for readiness, and is idempotent. It also explicitly mentions Android is unsupported, distinguishing it from any potential Android boot tool (none in siblings). This is specific verb+resource with clear scope.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly states idempotency and the Android limitation ('Android emulator booting is not yet supported (start it manually)'), providing clear context for when to use (iOS) and when not (Android). It does not name alternative tools, but no sibling boot tools exist for Android.

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