TSR: Trajectory-Search Rollouts for Multi-Turn RL of LLM Agents

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Djuhera, Aladin, Kadhe, Swanand Ravindra, Ahmed, Farhan, Zawad, Syed, Ludwig, Heiko, Boche, Holger
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866916023753506816
author Djuhera, Aladin
Kadhe, Swanand Ravindra
Ahmed, Farhan
Zawad, Syed
Ludwig, Heiko
Boche, Holger
author_facet Djuhera, Aladin
Kadhe, Swanand Ravindra
Ahmed, Farhan
Zawad, Syed
Ludwig, Heiko
Boche, Holger
contents Advances in large language models (LLMs) are driving a shift toward using reinforcement learning (RL) to train agents from iterative, multi-turn interactions across tasks. However, multi-turn RL remains challenging as rewards are often sparse or delayed, and environments can be stochastic. In this regime, naive trajectory sampling can hinder exploitation and induce mode collapse. We propose TSR (Trajectory-Search Rollouts), a training-time approach that repurposes test-time scaling ideas for improved per-turn rollout generation. TSR performs lightweight tree-style search to construct high-quality trajectories by selecting high-scoring actions at each turn using state-based feedback. This improves rollout quality and stabilizes learning while remaining compatible with standard policy gradient optimizers, making TSR optimizer-agnostic. We instantiate TSR with best-of-N, beam, and shallow lookahead search, and pair it with PPO and GRPO, achieving up to 15% performance gains and more stable learning on Sokoban, FrozenLake, and WebShop tasks at a modest, one-time increase in training compute. By moving search from inference time to the rollout stage of training, TSR provides a modular and general mechanism for stronger multi-turn agent learning, complementary to existing frameworks and rejection-sampling-style selection methods.
format Preprint
id arxiv_https___arxiv_org_abs_2602_11767
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle TSR: Trajectory-Search Rollouts for Multi-Turn RL of LLM Agents
Djuhera, Aladin
Kadhe, Swanand Ravindra
Ahmed, Farhan
Zawad, Syed
Ludwig, Heiko
Boche, Holger
Artificial Intelligence
Computation and Language
Machine Learning
Advances in large language models (LLMs) are driving a shift toward using reinforcement learning (RL) to train agents from iterative, multi-turn interactions across tasks. However, multi-turn RL remains challenging as rewards are often sparse or delayed, and environments can be stochastic. In this regime, naive trajectory sampling can hinder exploitation and induce mode collapse. We propose TSR (Trajectory-Search Rollouts), a training-time approach that repurposes test-time scaling ideas for improved per-turn rollout generation. TSR performs lightweight tree-style search to construct high-quality trajectories by selecting high-scoring actions at each turn using state-based feedback. This improves rollout quality and stabilizes learning while remaining compatible with standard policy gradient optimizers, making TSR optimizer-agnostic. We instantiate TSR with best-of-N, beam, and shallow lookahead search, and pair it with PPO and GRPO, achieving up to 15% performance gains and more stable learning on Sokoban, FrozenLake, and WebShop tasks at a modest, one-time increase in training compute. By moving search from inference time to the rollout stage of training, TSR provides a modular and general mechanism for stronger multi-turn agent learning, complementary to existing frameworks and rejection-sampling-style selection methods.
title TSR: Trajectory-Search Rollouts for Multi-Turn RL of LLM Agents
topic Artificial Intelligence
Computation and Language
Machine Learning
url https://arxiv.org/abs/2602.11767