Training on successful agent trajectories can introduce noisy supervision because successful trajectories may contain ineffective, redundant, or risky steps

task success does not guarantee high-quality supervision: successful trajectories may still contain ineffective, redundant, or risky steps. Directly using such trajectories for SFT can introduce noisy supervision and encourage models to imitate undesirable problem-solving behaviors.

http://arxiv.org/abs/2608.27449v1