Loading ToolBench
Control macOS system settings, apps, windows, audio, displays, screenshots, and Focus mode via MCP. STDIO or Streamable HTTP.
Strong tool definitions with comprehensive descriptions (avg 180 chars, well above 34-char baseline) and complete input schemas using Zod. All 10 tools have clear verb-noun naming (macos_check_*, macos_control_*, macos_manage_*). Tool annotations present (readOnlyHint, destructiveHint). Key gaps: output schemas not visible in provided source (only input schemas shown); error handling guidance minimal; some parameter descriptions could be more prescriptive about constraints and recovery paths.
Reports which macOS permissions relevant to this server are currently granted for the calling process: Accessibility (required for window manipulation, app hide/show), Screen Recording (required for window screenshots), Automation > Finder (required for Finder selection), and Notifications. Use this tool before attempting operations that require elevated permissions to confirm prerequisites without triggering an OS permission prompt.
Get or set the system appearance (dark mode or light mode). The get action returns the current mode. The set action accepts mode="dark", "light", or "toggle". Setting "dark" or "light" is idempotent — calling twice produces the same state. "toggle" flips the current mode on each call.
Manage audio device routing: list all input and output devices, get the current default input and output devices, or switch the default input or output device. Device names support case-insensitive partial matching — "MacBook" matches "MacBook Pro Microphone". Volume level control is separate (use macos_control_volume). Requires SwitchAudioSource CLI (brew install switchaudio-osx).
System-level power controls: lock the screen (⌃⌘Q shortcut via Accessibility; falls back to ScreenSaverEngine binary if Accessibility is not granted) or put the display to sleep immediately. Both operations are immediate and user-reversible (wake/unlock with any input).
Output schemas not visible in source code. Only input schemas provided; return types inferred from descriptions. Cannot verify structured output compliance or field naming consistency for chaining.
Error handling guidance absent. Tool descriptions state what they do but do not explain recovery paths (e.g., 'If permission denied, call macos_check_permissions first'). LLMs lack actionable next steps on failure.
Parameter constraints under-specified. 'device' in macos_control_audio accepts 'case-insensitive partial matching' but no regex or length bounds stated. 'mode' in macos_manage_focus must 'exactly match configured Focus profiles' but no enum provided, LLM must guess valid values.
Inferred effective spec: <=2025-11-25.
| Scored | Grade | Overall | Spec posture | Rubric |
|---|---|---|---|---|
| 2026-09-23 | C | 63 | <=2025-11-25 | v2 |
Get or set the system output volume level (0–100) and mute state. The get action returns the current level and mute state. The set action accepts level (0–100), muted (true/false), or both. Setting level=0 does not mute — use muted=true for explicit muting.
Returns a snapshot of the current macOS system state: battery level and charging status, power source (AC/Battery), Wi-Fi SSID, hostname, macOS version, uptime in seconds, and connected display count. All fields reflect live system state at the time of the call.
Manage application lifecycle: list all running user-facing apps, get the frontmost app, launch or activate an app, gracefully quit or force-quit a process, or hide/show an app. Launch activates the app if already running; use hidden=true to start in the background without bringing it forward. Force-quit terminates immediately (SIGKILL) without saving. Hide and show require Accessibility permission.
List connected displays with their current layout (resolution, position, rotation, scaling) and optionally apply a pre-configured display layout by name. Requires displayplacer CLI (brew install jakehilborn/jakehilborn/displayplacer). Layouts are pre-configured in the MACOS_DISPLAY_LAYOUTS environment variable as a JSON object mapping names to displayplacer argument strings. Layout application only accepts named presets — raw displayplacer args are never accepted from the user.
Finder integration: get the path of the frontmost Finder window, get the current Finder selection, reveal a file or folder in Finder, open a path with a specific app, or move a path to the Trash (recoverable — goes to Trash, not rm). Frontmost path and reveal work without any special permissions. get_selection requires Automation > Finder permission. trash moves files to Trash, not permanent deletion.
Get or set Do Not Disturb / Focus mode. The get action is best-effort — macOS 13+ protects the Focus state database and the returned status may be "unknown" on some configurations. The set action requires the built-in "Set Focus" shortcut to exist in the Shortcuts app (present on macOS 12+). Mode names must exactly match configured Focus profiles (e.g. "Do Not Disturb", "Work", "Personal").
Dependency on external CLIs (SwitchAudioSource, displayplacer) documented in descriptions but no fallback or graceful degradation strategy visible. If CLI missing, tool will fail with unclear error.
Destructive operations (force_quit, trash, lock screen) lack confirmation or dry-run support. Agents can irreversibly delete files or force-quit apps without user approval.