arXiv AI

COBRA-Skills: Contextual Bandit-Guided Evolution for Agent Skill Optimization

COBRA‑Skills is a new framework that treats skill optimization for large language model agents as a budgeted sequential problem over a dynamically evolving candidate set. It uses contextual‑bandit prioritization to focus evaluations on promising or informative candidates and refines the skill population based on execution feedback. In experiments across six agent benchmarks and three target models, COBRA‑Skills outperforms existing methods, cuts optimization cost by 55–58 % compared to SkillOpt, and requires only 50 unique optimization examples per benchmark.

arXiv Machine Learning
Oct 12

CB-Orchestrator: Adaptive Workflow Optimization for LLM Agents via Contextual Bandits

CB-Orchestrator is an adaptive framework for optimizing large language model (LLM) agent workflows. It separates workflow generation—via evolutionary search—from workflow selection, which is treated as a contextual bandit problem to enable sample‑efficient learning. The approach reduces training‑phase API token usage by up to 40.55% and overall token overhead by at least 29.73%, while outperforming baselines on five benchmarks, including the MATH dataset.

By Jiahang Sun, Zhiwei Shang, Zhipiao Liu, Hongwei Yang, Guoqing Xie, Shuang Qiu, Zhongxiang Dai
arXiv AI
Oct 2

ActiveSaddler: Automated Curriculum Learning for Agent Harness Optimization

ActiveSaddler introduces automated curriculum learning for harness optimization, treating the evolving training curriculum as a non‑stationary bandit problem. It identifies reusable failure patterns, estimates learning progress for each, and balances revisiting known weaknesses with exploring new scenarios, allowing the curriculum to co‑evolve with the harness. Experiments on GAIA2 and Terminal‑Bench 2.0 show consistent improvements in harness performance, with Pass@1 gains of 4.4 and 7.5 percentage points over fixed‑order baselines.

By Sungho Park, Wonjoong Kim, Jue Zhang, Wook-Shin Han, Pengfei Gao, Chanyoung Park, Yongqiang Yao, Rao Fu, Elsie Nallipogu, Qingwei Lin, Victor R\"uhle
arXiv AI
Sep 15

SkillLift: Learning Dense Rubrics from Sparse Oracles for Efficient Skill Evolution

SkillLift introduces a method for efficiently evolving reusable procedural prompts (skills) in large language model agents by learning a dense rubric that aligns with sparse oracle evaluations. Instead of directly revising skill text based on costly full agent rollouts, the approach decouples skill search from oracle cost through a bilevel optimization framework: an inner loop uses a frozen rubric as a cheap surrogate to guide skill updates, while an outer loop periodically realigns the rubric using a small number of oracle rollouts via rank correlation. Experiments on complex agent task benchmarks demonstrate that SkillLift outperforms existing auto-skill methods while reducing token cost by 40–70% compared to frontier-evolving approaches.

By Haoxiang Kang, Ming Wen
arXiv Computation and Language
Nov 4

Evolving Memory, Learning to Meta-Control: Test-Time Adaptation for Experience-augmented LLM Agents

The paper introduces Online Meta-Control of Experience (OMCE), a framework that updates an agent’s experience memory and learns a meta-control policy during test-time adaptation. OMCE uses a lightweight contextual-bandit meta-controller to choose among four cognitive actions—DIRECT, EPISODE, GUIDE, and DISTILL—based on compact retrieval signals, thereby deciding when to invoke experience, which memory format to use, and when to consolidate new guidance. Experiments on four online adaptation benchmarks across four backbones show that OMCE can improve first-attempt success by up to 20.5 percentage points over the strongest baseline while reducing per-task token use by a factor of 5.7 to 62.5 relative to ACE with GPT‑5.2, and controlled ablations confirm the benefits of learned routing and ongoing policy adaptation.

By Zeyuan Zhao, Yuanyuan Shi, Peng Yu, Lingyue Fu, Shao Zhang, Ying Wen