AgenTRIM: Tool Risk Mitigation for Agentic AI

Roy Betser, Amit Giloni, Shamik Bose, Sindhu Padakandla, Chiara Picardi, Lidor Erez, Roman Vainshtein


Abstract
AI agents combine LLMs with external tools to solve complex tasks. While tools extend agents’ capabilities, improper permissions introduce risks such as indirect prompt injection and tool misuse. We characterize these failures as unbalanced tool-driven agency, a unified view in which agents either retain unnecessary permissions (excessive agency) or fail to invoke required tools (insufficient agency), increasing risk and reducing performance. We introduce AgenTRIM, a framework that addresses this imbalance without altering agent reasoning, through complementary offline and online stages. Offline, it reconstructs the agent’s tool interface from code and validates tool behavior via controlled executions and trace analysis. At runtime, it enforces per-step least-privilege access through adaptive capability filtering and isolated validation of tool calls, implicitly decomposing tasks without explicit planning. On the AgentDojo benchmark, AgenTRIM substantially reduces attack success while improving task performance over the baseline, unlike other leading defenses. To assess robustness beyond prompt injection, we conduct additional experiments covering description-based attacks and policy enforcement. Together, these results establish AgenTRIM as a general, capability-preserving framework for mitigating tool-driven risks in LLM-based agents.
Anthology ID:
2026.findings-emnlp.1102
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
23301–23325
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1102/
DOI:
10.18653/2026.findings-emnlp.1102
Bibkey:
Cite (ACL):
Roy Betser, Amit Giloni, Shamik Bose, Sindhu Padakandla, Chiara Picardi, Lidor Erez, and Roman Vainshtein. 2026. AgenTRIM: Tool Risk Mitigation for Agentic AI. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 23301–23325, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
AgenTRIM: Tool Risk Mitigation for Agentic AI (Betser et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.1102.pdf