Safety Sentry: Context-Aware Human Intervention via EXECUTE–ASK–REFUSE Routing

Tianyu Chen, Chujia Hu, Wenjie Wang


Abstract
LLM agents act on real-world environments through tool calls, and a single misjudged action can cause irreversible harm. The standard safeguard is a guard model that labels each proposed action as safe or unsafe, but this binary view conflates two distinct decisions: whether the action is harmful in itself, and whether it is appropriate given the user’s context. It also operates at the granularity of action categories rather than individual instances, producing routine interruptions that erode autonomy and train users to wave through the most consequential alerts. We reframe the problem as a per-instance three-way routing decision over Execute, Ask, Refuse and instantiate it with Safety Sentry, a lightweight guard model whose inference reduces to a single decoding call. A single decoding-time threshold lets one fixed checkpoint be re-positioned across deployments of differing risk tolerance without retraining. Safety Sentry outperforms a broad set of open-weight and frontier closed-source baselines on overall accuracy and safety-related recall, while controlling both directional error rates simultaneously.
Anthology ID:
2026.emnlp-main.724
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
16826–16852
Language:
URL:
https://aclanthology.org/2026.emnlp-main.724/
DOI:
Bibkey:
Cite (ACL):
Tianyu Chen, Chujia Hu, and Wenjie Wang. 2026. Safety Sentry: Context-Aware Human Intervention via EXECUTE–ASK–REFUSE Routing. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 16826–16852, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Safety Sentry: Context-Aware Human Intervention via EXECUTE–ASK–REFUSE Routing (Chen et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.724.pdf