agent-device

Official

by callstack

Overview Schema Source Related Servers Discussions Admin

TypeScript

Remote

boot

Boots or prepares the selected device or simulator so subsequent commands can target it, with a 90-second time-out.

Instructions

Boot or prepare the selected device or simulator so later commands can target it. The device is chosen through the device-selection inputs, not by naming it here. Times out after 90s.

Input Schema

TableJSON Schema

Name	Required	Description
`udid`	No	Apple device or simulator UDID; the selector that pins one device when several share a name.
`debug`	No	Enable debug diagnostics.
`runId`	No	Lease run identifier.
`device`	No	Device name selector (a UDID belongs in udid, a serial in serial).
`serial`	No	Android, HarmonyOS, or Vega VVD serial selector.
`target`	No	Alias for deviceTarget on commands without a UI target field. Interaction commands reserve target for the UI element.
`tenant`	No	Remote tenant identifier.
`leaseId`	No	Existing lease identifier.
`session`	No	Agent-device session name.
`headless`	No	Boot without showing simulator UI when supported.
`platform`	No	Platform selector used to resolve a device.
`includeCost`	No	Include per-command agent-cost (cost.wallClockMs, …) in structuredContent. Defaults to off; the default response shape is unchanged.
`deviceTarget`	No	Device target form. Maps to the CLI --target flag.
`responseLevel`	No	Response verbosity: token-cheap digest / default (today) / full. Defaults to default; the default response shape is unchanged.
`mcpOutputFormat`	No	MCP text content format. Defaults to optimized agent-friendly text; use json for JSON text. Structured content is always returned separately.
`androidDeviceAllowlist`	No	Android serial allowlist used for device resolution.

Output Schema

TableJSON Schema

Name	Required	Description
`id`	Yes	Stable device id.
`kind`	Yes
`booted`	Yes
`device`	Yes	Human-readable device name.
`target`	Yes
`platform`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedv0.21.0Sep 9, 2026

changedInput schema / properties / device / description

Previous value: -"Device name selector."New value: +"Device name selector (a UDID belongs in udid, a serial in serial)."

changedInput schema / properties / serial / description

Previous value: -"Android device or Vega VVD serial selector."New value: +"Android, HarmonyOS, or Vega VVD serial selector."

changedInput schema / properties / udid / description

Previous value: -"iOS device UDID selector."New value: +"Apple device or simulator UDID; the selector that pins one device when several share a name."

Changed8 schema fields changedv0.20.10Aug 26, 2026

removedInput schema / properties / cwd

Removed value: -{
-  "description": "Working directory for command execution.",
-  "type": "string"
-}

removedInput schema / properties / daemonAuthToken

Removed value: -{
-  "description": "Remote daemon auth token.",
-  "type": "string"
-}

removedInput schema / properties / daemonBaseUrl

Removed value: -{
-  "description": "Remote daemon base URL.",
-  "type": "string"
-}

removedInput schema / properties / iosSimulatorDeviceSet

Removed value: -{
-  "description": "iOS simulator device-set path used for device resolution.",
-  "type": "string"
-}

removedInput schema / properties / iosXctestDerivedDataPath

Removed value: -{
-  "description": "Derived data path for external iOS XCTest runner execution.",
-  "type": "string"
-}

removedInput schema / properties / iosXctestEnvDir

Removed value: -{
-  "description": "Writable directory for iOS XCTest runner env overlays.",
-  "type": "string"
-}

removedInput schema / properties / iosXctestrunFile

Removed value: -{
-  "description": "Externally built iOS XCTest runner .xctestrun artifact path.",
-  "type": "string"
-}

removedInput schema / properties / stateDir

Removed value: -{
-  "description": "Agent-device state directory.",
-  "type": "string"
-}

Changed2 schema fields changedv0.20.9Aug 19, 2026

changedInput schema / properties / platform / enum

Previous value: -[
-  "apple",
-  "android",
-  "vega",
-  "linux",
-  "web",
-  "ios",
-  "macos"
-]New value: +[
+  "apple",
+  "android",
+  "harmonyos",
+  "vega",
+  "linux",
+  "web",
+  "ios",
+  "macos"
+]

changedOutput schema / properties / platform / enum

Previous value: -[
-  "ios",
-  "macos",
-  "android",
-  "vega",
-  "linux",
-  "web"
-]New value: +[
+  "ios",
+  "macos",
+  "android",
+  "harmonyos",
+  "vega",
+  "linux",
+  "web"
+]

Changed3 schema fields changedv0.20.2Jul 30, 2026

changedInput schema / properties / platform / enum

Previous value: -[
-  "apple",
-  "android",
-  "linux",
-  "web",
-  "ios",
-  "macos"
-]New value: +[
+  "apple",
+  "android",
+  "vega",
+  "linux",
+  "web",
+  "ios",
+  "macos"
+]

changedInput schema / properties / serial / description

Previous value: -"Android serial selector."New value: +"Android device or Vega VVD serial selector."

changedOutput schema / properties / platform / enum

Previous value: -[
-  "apple",
-  "android",
-  "linux",
-  "web"
-]New value: +[
+  "ios",
+  "macos",
+  "android",
+  "vega",
+  "linux",
+  "web"
+]

Changed4 schema fields changedv0.17.11Jul 6, 2026

addedInput schema / properties / includeCost

Added value: +{
+  "description": "Include per-command agent-cost (cost.wallClockMs, …) in structuredContent. Defaults to off; the default response shape is unchanged.",
+  "type": "boolean"
+}

changedInput schema / properties / platform / enum

Previous value: -[
-  "ios",
-  "macos",
-  "android",
-  "linux",
-  "web",
-  "apple"
-]New value: +[
+  "apple",
+  "android",
+  "linux",
+  "web",
+  "ios",
+  "macos"
+]

addedInput schema / properties / responseLevel

Added value: +{
+  "description": "Response verbosity: token-cheap digest / default (today) / full. Defaults to default; the default response shape is unchanged.",
+  "enum": [
+    "digest",
+    "default",
+    "full"
+  ],
+  "type": "string"
+}

changedOutput schema / (root)

Previous value: -nullNew value: +{
+  "properties": {
+    "booted": {
+      "const": true,
+      "type": "boolean"
+    },
+    "device": {
+      "description": "Human-readable device name.",
+      "type": "string"
+    },
+    "id": {
+      "description": "Stable device id.",
+      "type": "string"
+    },
+    "kind": {
+      "enum": [
+        "simulator",
+        "emulator",
+        "device"
+      ],
+      "type": "string"
+    },
+    "platform": {
+      "enum": [
+        "apple",
+        "android",
+        "linux",
+        "web"
+      ],
+      "type": "string"
+    },
+    "target": {
+      "enum": [
+        "mobile",
+        "tv",
+        "desktop"
+      ],
+      "type": "string"
+    }
+  },
+  "required": [
+    "platform",
+    "target",
+    "device",
+    "id",
+    "kind",
+    "booted"
+  ],
+  "type": "object"
+}

Changed1 schema field changedv0.17.7Jun 23, 2026

changedInput schema / properties / platform / enum

Previous value: -[
-  "ios",
-  "macos",
-  "android",
-  "linux",
-  "apple"
-]New value: +[
+  "ios",
+  "macos",
+  "android",
+  "linux",
+  "web",
+  "apple"
+]

Changed5 schema fields changedv0.17.6Jun 18, 2026

addedInput schema / properties / iosXctestDerivedDataPath

Added value: +{
+  "description": "Derived data path for external iOS XCTest runner execution.",
+  "type": "string"
+}

addedInput schema / properties / iosXctestEnvDir

Added value: +{
+  "description": "Writable directory for iOS XCTest runner env overlays.",
+  "type": "string"
+}

addedInput schema / properties / iosXctestrunFile

Added value: +{
+  "description": "Externally built iOS XCTest runner .xctestrun artifact path.",
+  "type": "string"
+}

addedInput schema / properties / mcpOutputFormat

Added value: +{
+  "description": "MCP text content format. Defaults to optimized agent-friendly text; use json for JSON text. Structured content is always returned separately.",
+  "enum": [
+    "optimized",
+    "json"
+  ],
+  "type": "string"
+}

changedInput schema / properties / platform / enum

Previous value: -[
-  "ios",
-  "android",
-  "macos",
-  "linux",
-  "apple"
-]New value: +[
+  "ios",
+  "macos",
+  "android",
+  "linux",
+  "apple"
+]

First observedv0.16.9Jun 3, 2026

TDQS

A4/5.0

Behavior3/5

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

No annotations are provided, so the description must carry the behavioral transparency burden. It usefully discloses a 90-second timeout and the selection mechanism. It does not describe side effects, idempotency, whether boot waits for readiness, or failure behavior beyond timing, so it provides only partial behavioral context.

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?

Three terse sentences front-load the core action, then clarify device selection and add the timeout. Every sentence contributes operational information, no repetition of schema content, and no irrelevant details.

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 all 16 parameters described in the schema and an output schema available, the description correctly avoids restating parameter details. It supplies the missing context: device resolution approach, follow-up readiness, and 90-second timeout. Minor gaps remain around whether boot is asynchronous and how an already-booted device is handled, but the definition is adequate for selecting and invoking the tool correctly.

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?

The schema already documents all 16 parameters, so the baseline is 3. The description adds value by clarifying that no device name is passed directly and that the target is resolved via the device-selection inputs. This helps an agent understand how to populate selector parameters correctly rather than looking for a 'name' field.

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 states a clear action ('Boot or prepare') with a specific resource ('selected device or simulator') and the intended outcome ('so later commands can target it'). This distinguishes it from device-management siblings like shutdown or devices by focusing on bringing the device into a usable state.

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

Usage Guidelines3/5

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

It clearly implies when to use it: before later commands that target the device. It also advises that the device is chosen through device-selection inputs, not by naming it directly. However, it does not explicitly state when not to use it or mention sibling alternatives such as shutdown or open.

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

Deploy Server

boot

Instructions

Input Schema

Output Schema

Schema Changelog

TDQS

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