DeepPlanning: Benchmarking Long-Horizon Agentic Planning with Verifiable Constraints
Yinger Zhang, Shutong Jiang, Renhao Li, Jianhong Tu, Yang Su, Lianghao Deng, Xudong Guo, Chenxu Lv, Junyang Lin
TL;DR
DeepPlanning addresses the need for evaluating long-horizon, agentic planning under global constraints by introducing a two-domain benchmark (Travel Planning and Shopping Planning) with a three-stage data-generation pipeline and verifiable, offline sandboxes. It formalizes three core competencies—proactive information acquisition, local constrained reasoning, and global constrained optimization—and provides code-based evaluation to reveal fundamental limitations of frontier LLMs in sustained planning. Across diverse model families, results show planning fragility, where partial correctness does not guarantee executable plans, and demonstrate that internal reasoning enhances both effectiveness and efficiency. The work highlights key directions for strengthening agentic LLMs over extended horizons and provides a practical, open-source platform to drive advances in grounded, long-horizon planning.
Abstract
While agent evaluation has shifted toward long-horizon tasks, most benchmarks still emphasize local, step-level reasoning rather than the global constrained optimization (e.g., time and financial budgets) that demands genuine planning ability. Meanwhile, existing LLM planning benchmarks underrepresent the active information gathering and fine-grained local constraints typical of real-world settings. To address this, we introduce DeepPlanning, a challenging benchmark for practical long-horizon agent planning. It features multi-day travel planning and multi-product shopping tasks that require proactive information acquisition, local constrained reasoning, and global constrained optimization. Evaluations on DeepPlanning show that even frontier agentic LLMs struggle with these problems, highlighting the importance of reliable explicit reasoning patterns and parallel tool use for achieving better effectiveness-efficiency trade-offs. Error analysis further points to promising directions for improving agentic LLMs over long planning horizons. We open-source the code and data to support future research.
