Paper Overview
- Field: Machine Learning
- Authors: Xuhao Hu, Xi Zhang, Haiyang Xu, Kyle Qiao, Jingyi Yang, Xuanjing Huang, Jing Shao, Ming Yan, Jieping Ye
- Released: 2026-05-12
- arXiv: 2605.12481
- Scarcity of high-quality interleaved GUI-Tool trajectories
- The cost and brittleness of collecting real tool trajectories
- Lack of trajectory-level supervision for GUI-Tool path selection
- On OSWorld-MCP, ToolCUA achieves 46.85% accuracy, about a 66% relative improvement over baselines.
- Establishes a new state-of-the-art among comparable-scale models.
- A 3.9% improvement over the pure GUI setting demonstrates the effectiveness of GUI-Tool orchestration.
- Hybrid GUI + tool action spaces require explicit orchestration; current agents lack trajectory-level supervision for switching decisions.
- A synthetic data pipeline can replace costly real tool trajectory collection by augmenting static GUI trajectories with grounded tool libraries.
- Staged training (SFT → single-turn RL → online agentic RL with tool-efficiency rewards) is effective for teaching optimal GUI-Tool path selection.
- ToolCUA delivers substantial accuracy gains on OSWorld-MCP and validates that mixing GUI actions with tool calls outperforms GUI-only execution.
Summary
Computer Use Agents (CUAs) can act through both atomic GUI actions, such as click and type, and high-level tool calls, such as API-based file operations. However, this hybrid action space often leaves them uncertain about when to continue with GUI actions versus switch to tools, leading to suboptimal execution paths. The difficulty stems from:
This paper proposes ToolCUA, an end-to-end agent designed to learn optimal GUI-Tool path selection through a staged training paradigm.
Method
1. Interleaved GUI-Tool Trajectory Scaling Pipeline — repurposes abundant static GUI trajectories and synthesizes grounded tool libraries, enabling diverse GUI-Tool trajectories without manual engineering or real tool trajectory collection. 2. Tool-Guided GUI RFT — combines warm-up SFT with single-turn RL to improve decisions at critical GUI-Tool switching points. 3. Online Agentic RL in a High-Fidelity GUI-Tool Environment — optimizes ToolCUA further, guided by tool-efficient path rewards that encourage appropriate tool usage and shorter execution paths.