AgentGen: Enhancing Planning Abilities for Large Language Model based Agent via Environment and Task Generation

Large Language Model (LLM) based agents have garnered significant attention and are becoming increasingly popular. Furthermore, planning ability is a crucial component of an LLM-based agent, involving interaction with the environment and executing actions to complete a planning task, which generally entails achieving a desired goal from an initial state. This paper investigates enhancing the planning abilities of LLM-based agents through instruction tuning, referred to as agent training. Recent studies on agent training have demonstrated that utilizing expert-level trajectory data (sequences of action-observation pairs) for instruction-tuning LLMs effectively enhances their planning capabilities. However, existing work primarily focuses on synthesizing trajectories from manually designed planning tasks and environments. The labor-intensive nature of creating these environments and tasks impedes the generation of sufficiently varied and extensive trajectories for agent training. To address this limitation, this paper explores the automated synthesis of diverse environments and a gradual range of planning tasks, from easy to difficult. We introduce a framework, AgentGen, that leverages LLMs first to generate environments and subsequently generate planning tasks conditioned on these environments. Specifically, to improve environmental diversity, we propose using an inspiration corpus composed of various domain-specific text segments as the context for synthesizing environments. Moreover, to increase the difficulty diversity of generated planning tasks, we propose a bidirectional evolution method, Bi-Evol, that evolves planning tasks from easier and harder directions to synthesize a task set with a smoother difficulty curve, thereby enhancing the learning process of LLMs more effectively. These methods collectively contribute to the generation of diverse trajectory data for instruction-tuning. Based on AgentGen, we greatly expanded the number of environments and planning tasks available for agent training. The evaluation results from AgentBoard indicate that AgentGen greatly enhances the planning capabilities of LLMs. For instance, the AgentGen instruction-tuned Llama-3.1-8B outperforms GPT-3.5 in overall performance. Moreover, the AgentGen-tuned Llama-3.1-70B model achieves state-of-the-art results in planning tasks. Project page: https://agent-gen.github.io/.