@article{skillscoachaselfevolvingskilloptimizervi,
  title = {Skills-Coach: A Self-Evolving Skill Optimizer via Training-Free GRPO},
  author = {Yu Tian and Jiawei Chen and Lifan Zheng and Mingxiang Tao and Xinyi Zeng and Zhaoxia Yin and Hang Su and Xian Sun},
  year = {2026},
  eprint = {2604.27488},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2604.27488},
}