arXiv AI

Bench2Robust: Scenario-Controlled Recovery for Tool-Using Agents

Bench2Robust is a framework that augments existing tool‑using LLM benchmarks with scenario‑controlled solvability, adding episodes that require retrying the original path, switching to a fallback tool, or recognizing that no viable path remains. It separates recovery‑policy quality from randomness in failure persistence, and across 7 models and 10 task slices, 69 of 70 model‑subset pairs degrade under tool failures by up to 46.7 percentage points. The authors introduce Bayesian Tool Memory (BTM) for structured runtime recovery context and use reinforcement learning (RL) for learned recovery behavior, achieving up to a 20.7‑point improvement over the base model without sacrificing clean performance.

arXiv AI
Aug 13

Retry, Switch, or Abstain? Learning Strategy-Aware Tool-Use Policies via Controlled Error Injection

arXiv:2608. 11977v1 Announce Type: new Abstract: Tool-using LLM agents are commonly trained and evaluated in environments where tool calls succeed reliably, yet deployed tools can fail transiently, persistently, or silently.

By Chaoran Chen, Vy Nguyen, Ziji Zhang, Abhinav Gullapalli, Ziyi Wang, Yuxuan Lu, Dakuo Wang, Jing Huang, Zhou Yu, Jin Lai
arXiv Machine Learning
Sep 24

Learning from Failures: Heterogeneous Graph Memory for Small Language Model Tool-Using Agents

The paper introduces FRESH, a Failure-aware Retrieval framework that uses Experience-Structured Heterogeneous graphs to transform past successes and failures into structured external memory for tool‑using agents. By explicitly modeling dependencies among tasks, actions, errors, repairs, and execution conditions, FRESH enables frozen language models to reuse reliable strategies, avoid recurring failures, and make safer decisions in stateful tool interactions. Experiments on τ‑Bench and AppWorld with multiple open‑source models demonstrate that FRESH consistently improves task success and tool‑use reliability compared to no‑memory agents and other memory‑based baselines.

By Jiaxing Li, Lei Song, Rui Dong, Youyong Kong
arXiv AI
Oct 12

When Simulation Lies: A Sim-to-Real Benchmark and Domain-Randomized RL Recipe for Tool-Use Agents

The paper introduces RobustBench‑TC, a benchmark that tests tool‑use language agents under 22 real‑world perturbations affecting observations, actions, rewards, and transitions. Experiments on 21 models show that observation noise has minimal impact, while reward‑relevant and transition noise drastically reduce accuracy, and model size alone does not mitigate these gaps. The authors propose ToolRL‑DR, a domain‑randomized reinforcement‑learning recipe that improves robustness, retaining most clean accuracy and narrowing performance gaps even on unseen transition perturbations.

By Xiaolin Zhou, Aojie Yuan, Zheng Luo, Zipeng Ling, Xixiao Pan, Yicheng Gao, Haiyue Zhang, Jiate Li, Shuli Jiang, Prince Zizhuang Wang, Zixuan Zhu, Jinbo Liu, Ryan A. Rossi, Hua Wei, Xiyang Hu
arXiv Machine Learning
Sep 14

ParaRecover: A Process-Level Benchmark for Error Localization and Recovery in Parallel Tool-Use Agents

ParaRecover is a new process-level benchmark designed to evaluate error localization and recovery in multi-turn parallel tool-use agents. It contains 10,626 instances across two difficulty levels, built on a taxonomy of 14 error types that cover planning dependencies, tool selection, and argument matching. The benchmark introduces the SDE rubric, which assesses structural integrity, diagnostic reasoning, and evolutionary strategy during agent execution, and demonstrates that it can guide improvements in agents’ reflective recovery capabilities.

By Bowen Guan, Zhentao Yin, Yanming Shen
arXiv AI
Sep 25

Grow the Harness, Not the Context: From Strategy-Free Scaffolds to Reusable Specialist Agents

The paper introduces Growing Harness, a training method that transforms recurring control logic in large language model agents into reusable executable code, reducing reliance on the model for task-specific decisions. By using strategy-free scaffolds, failure-guided code repair, and success-first gating, the approach learns a shared harness that improves performance across multiple benchmarks and model sizes. Experiments on BrowseComp-Plus and WebArena-Verified show significant gains in success rates and substantial reductions in LLM calls and inference cost compared to traditional tool‑calling agents.

By Laizhen Li, Jiarui Li, Juanjuan Zhao, Kejiang Ye, Ye Li, Cheng-zhong Xu, Xitong Gao
arXiv AI
Oct 12

RATED: Reliability-Aware AI Agent Tool Retrieval via Execution Dynamics

RATED (Reliability‑Aware Tool Retrieval via Execution Dynamics) is a retrieval framework that blends robust semantic matching with dynamic reliability adaptation for AI agents using external tools. It uses a frozen dual‑encoder with contrastive fine‑tuning for semantic relevance and a lightweight contextual bandit module that re‑ranks tool candidates based on real‑time execution feedback, allowing rapid adaptation to runtime failures without costly retraining. The EcoAgent benchmark, comprising 5,172 real‑world tools and over 210,000 query‑tool pairs, shows that RATED improves mean reciprocal rank by 52.2% over the ToolLLM API retriever and cuts fault selection from 86.2% to 2.9% during severe API outages, with negligible latency overhead.

By Weiliang Chen, Song Liao