Iterative Tool Usage Exploration for Multimodal Agents via Step-wise Preference Tuning - Li, Pengxiang; Gao, Zhi; Zhang, Bofei; Mi, Yapeng; Ma, Xiaojian (Shawn); Shi, Chenrui; Yuan, Tao; Wu, Yuwei; Jia, Yunde; Zhu, Song-Chun; Li, Qing (Advances in Neural Information Processing Systems, 2025)