Taming “Zombie” Agents: A Markov State-Aware Framework for Resilient Multi-Agent Evolution
Paper · 2026 · Taolin Zhang, Pukun Zhao, Qizhou Chen et al.
Summary
LLM-based multi-agent systems often save compute by pruning agents or links from the communication graph. These cuts are permanent. An agent that fails for a moment, through a hallucination or a knowledge gap, is removed even if it could have helped in later rounds. The authors call such agents "zombie" agents. Their framework, AgentRevive, treats collaboration as a Markov decision process and gives each agent one of three states: Active, Standby or Terminated. A lightweight policy network decides each round's transitions from:
- the agent's previous state,
- its own answer,
- the messages it receives.
The reward combines task accuracy, token cost and a hallucination-risk penalty. A second stage builds a binary node mask from agent survival rates and applies it to the spatial and temporal adjacency matrices. Terminated agents are removed for good, while Standby agents remain available and can be revived. Across general reasoning, domain-specific and hallucination benchmarks, AgentRevive beats pruning-based and autoregressive graph-generation baselines. It also uses fewer tokens, which suggests that reversible agent scheduling is more efficient and more robust than hard pruning.
Key points
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Overall results: averaged across tasks, accuracy rises by about +2.33% over strong baselines (AgentPrune, AgentDropout, ARG-Designer), and token overhead falls by about 15%.
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MMLU efficiency test (Llama3-8B, one A100): accuracy is 64.30% for AgentRevive, compared with:
- AgentDropout: 62.75%
- ARG-Designer: 61.49%
- fixed MAS round=T: 60.13%
Token use drops from 1.99M to 1.32M (−33.7%). Inference costs 1.75 s/sample against 1.62 s for AgentDropout. Training takes 20.8 GPU hours against 15.2.
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What drives transitions: a logistic-regression analysis shows that moving from Standby back to Active is linked mainly to high message information gain (0.69). Higher self-risk pushes agents out of Active.
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Robustness: the method stays robust under prompt attacks and under different initial graph shapes (Layered, Random).
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Limitations: experiments use at most 5 agents. The hyperparameters were set to γ = 0.6 and η_risk = 0.5 without broad tuning. The policy network is a simple MLP.
Institutions
Fields, topics and concepts
📚 Shelves 4The field of science this work belongs to (OpenAlex fields).Computer Science · 18,614 worksArtificial Intelligence · 17,965 worksArts and Humanities · 17,450 worksLanguage and Linguistics · 17,296 works
Cite
Cite as Taolin Zhang, Pukun Zhao, Qizhou Chen, Jiuheng Wan, Chen Chen, Xiaofeng He, Chengyu Wang and Richang Hong. 2026. Taming “Zombie” Agents: A Markov State-Aware Framework for Resilient Multi-Agent Evolution. Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers).
@inproceedings{zhang2026taming,
title = {{Taming “Zombie” Agents: A Markov State-Aware Framework for Resilient Multi-Agent Evolution}},
author = {Taolin Zhang, Pukun Zhao, Qizhou Chen, Jiuheng Wan, Chen Chen, Xiaofeng He, Chengyu Wang and Richang Hong},
booktitle = {Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)},
year = {2026},
doi = {10.18653/v1/2026.acl-long.373},
url = {https://doi.org/10.18653/v1/2026.acl-long.373}
}References
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