End-to-End Differentiable Optimization of Tool-Augmented Visual Reasoning via Probabilistic Graphs

Wentao Wan, Kaiyu Wu, Qingyang Ma, Nan Kang, Yunjie Chen, Liang Lin, Keze Wang


Abstract
Tool-augmented visual reasoning systems, exemplified by Visual Programming (VP), decompose complex visual questions into executable programs that invoke specialized visual models as tools, offering interpretable and compositional reasoning. However, these systems face a fundamental optimization challenge: the non-differentiable pipeline and the absence of intermediate supervision prevent end-to-end gradient-based optimization of invoked tools using only task-level labels. Existing methods either optimize the Large Language Model (LLM) planner while neglecting tool quality, or rely on teacher models and additional data collection, none achieving true end-to-end differentiable optimization. We propose **eDoT**, the first **e**nd-to-end **D**ifferentiable **o**ptimization method for **T**ool-augmented visual reasoning. Our key insight is that any program’s variable dependency structure is isomorphic to a directed probabilistic graph. Applying Variable Elimination - an exact probabilistic inference technique - transforms the non-differentiable VP execution into a fully differentiable process, enabling gradient-based optimization with only task-level supervision, without additional data or teacher models. Experiments on GQA, NLVRv2 and Open Images demonstrate improvements of 3.7%, 7.6% and 20%, validating eDoT’s effectiveness across multiple visual models and cross-task generalization.
Anthology ID:
2026.findings-emnlp.2444
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
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Pages:
52467–52482
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2444/
DOI:
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Cite (ACL):
Wentao Wan, Kaiyu Wu, Qingyang Ma, Nan Kang, Yunjie Chen, Liang Lin, and Keze Wang. 2026. End-to-End Differentiable Optimization of Tool-Augmented Visual Reasoning via Probabilistic Graphs. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 52467–52482, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
End-to-End Differentiable Optimization of Tool-Augmented Visual Reasoning via Probabilistic Graphs (Wan et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2444.pdf