macos-control-mcp

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get_ui_elements

Retrieve the accessibility tree of a macOS app window, including UI element roles, names, and positions. Identify specific interface elements for automation.

Instructions

Get the accessibility tree of an app window. Returns UI element roles, names, and positions.

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": {
      "app": "<app>"
    },
    "name": "get_ui_elements"
  }
}

Input Schema

Name	Required	Description	Default
`app`	Yes	Application process name

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.0.13May 29, 2026

TDQS

A3.7/5.0

Behavior3/5

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

Description implies read-only operation but does not disclose performance implications, permission requirements, or behavioral details beyond what is stated. Adequate for a simple getter.

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?

Single sentence, front-loaded with action and resource. No wasted words; perfectly concise.

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

Completeness5/5

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

Tool is simple with one required parameter. No output schema, but description covers what is returned. Complete for its purpose.

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

Parameters3/5

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

Only one parameter 'app' with schema description 'Application process name'. Schema coverage is 100%, so description adds no extra meaning beyond the schema. Baseline score.

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?

Clearly states the action ('Get'), resource ('accessibility tree of an app window'), and return values ('UI element roles, names, and positions'). Distinguishes from siblings like get_page_elements (web) and screen_ocr (image-based).

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

Usage Guidelines2/5

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

No guidance on when to use this tool versus alternatives (e.g., get_page_elements for web, screen_ocr for images). No mention of prerequisites or limitations.

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