mlsanityData to 7 Oct 2026

STRUCTUREDAGENT: Planning with AND/OR Trees for Long-Horizon Web Tasks

arXiv 2603.05294 ↗First posted 5 Mar 2026cs.AIcited by 1

On the map: LLM agents and tool use → Web, search, and research agents

Abstract (arXiv)

Existing LLM-based web agents struggle on complex, long-horizon tasks due to limited in-context memory, weak planning abilities, and greedy behaviors that lead to premature termination. To address these challenges, we propose SA, a hierarchical planning framework that interleaves planning and execution via dynamic ANDOR trees. The framework separates structural planning from LLM-based reasoning, enabling principled error recovery through node repair, systematic exploration of alternatives via OR nodes, and modular plans that can facilitate human intervention. On WebArena (630 tasks), SA achieves a ~53% success rate vs. ~46% for AgentOccam, and on complex multi-constraint Amazon shopping tasks, gains reach 10% over the strongest baseline.

Key facts. Cited by 1 paper in the map (data through 7 Oct 2026). Placed in Web, search, and research agents, one of 16 directions in LLM agents and tool use. Builds on 27 of its 63 references that are in the map. First posted on arXiv 5 Mar 2026.

Builds on

27 of 63 references.

Closest ancestors · 9

Same direction, newest first

  1. 2025BrowserAgent: Building Web Agents with Human-Inspired Web Browsing Actions12 Oct
  2. 2025BrowserArena: Evaluating LLM Agents on Real-World Web Navigation Tasks2 Oct
  3. 2024WebRL: Training LLM Web Agents via Self-Evolving Online Curriculum Reinforcement Learning4 Nov
  4. 2024AgentOccam: A Simple Yet Strong Baseline for LLM-Based Web Agents17 Oct
  5. 2024NNetNav: Unsupervised Learning of Browser Agents Through Environment Interaction in the Wild3 Oct
  6. 2024Agent Workflow Memory11 Sep
  7. 2024AutoWebGLM: A Large Language Model-based Web Navigating Agent4 Apr
  8. 2024WebVoyager: Building an End-to-End Web Agent with Large Multimodal Models25 Jan
  9. 2023WebArena: A Realistic Web Environment for Building Autonomous Agents25 Jul

Other references · 18

  1. 2023Reflexion: Language Agents with Verbal Reinforcement Learningcited by 4,064
  2. 2020Offline Reinforcement Learning: Tutorial, Review, and Perspectives on Open Problemscited by 1,873
  3. 2023CogAgent: A Visual Language Model for GUI Agentscited by 692
  4. 2023Language Agent Tree Search Unifies Reasoning Acting and Planning in Language Modelscited by 551
  5. 2024ArCHer: Training Language Model Agents via Hierarchical Multi-Turn RLcited by 212
  6. 2024DigiRL: Training In-The-Wild Device-Control Agents with Autonomous Reinforcement Learningcited by 210
  7. 2025Plan-and-Act: Improving Planning of Agents for Long-Horizon Taskscited by 190
  8. 2017Bridging the Gap Between Value and Policy Based Reinforcement Learningcited by 178
  9. 2023ADaPT: As-Needed Decomposition and Planning with Language Modelscited by 172
  10. 2024Android in the Zoo: Chain-of-Action-Thought for GUI Agentscited by 156
  11. 2024Tree Search for Language Model Agentscited by 148
  12. 2023A Survey of Imitation Learning: Algorithms, Recent Developments, and Challengescited by 145
6 more
  1. 2024WebPilot: A Versatile and Autonomous Multi-Agent System for Web Task Execution with Strategic Explorationcited by 100
  2. 2023SteP: Stacked LLM Policies for Web Actionscited by 66
  3. 2024Offline Reinforcement Learning for LLM Multi-Step Reasoningcited by 53
  4. 2024Unveiling the Secret Recipe: A Guide For Supervised Fine-Tuning Small LLMscited by 39
  5. 2025LLMs are Greedy Agents: Effects of RL Fine-tuning on Decision-Making Abilitiescited by 36
  6. 2025The Pitfalls of Imitation Learning when Actions are Continuouscited by 25

Built on by

Cited by year (2026 to 7 Oct)

Citing papers per year: 2026: 1.

1 paper.

  1. 2026The Evolution of Tool Use in LLM Agents: From Single-Tool Call to Multi-Tool Orchestrationcited by 11

Similar, not cited

Close in wording, no citation either way

  1. 2026AI Planning Framework for LLM-Based Web Agents
  2. 2026Why Do LLM-based Web Agents Fail? A Hierarchical Planning Perspective
  3. 2026Does The Way You Plan Matter? An Empirical Study of Planning Representations for LLM Web Agents
  4. 2025ReAcTree: Hierarchical LLM Agent Trees with Control Flow for Long-Horizon Task Planning
  5. 2025Branch-and-Browse: Efficient and Controllable Web Exploration with Tree-Structured Reasoning and Action Memory
  6. 2026Enhancing Web Agents with a Hierarchical Memory Tree
  7. 2025Robotouille: An Asynchronous Planning Benchmark for LLM Agents
  8. 2026GATS: Graph-Augmented Tree Search with Layered World Models for Efficient Agent Planning