Can Your Agent Read the Source Faithfully? Benchmarking MLLM Agents on Source-Grounded Multimodal Retrieval

Wentao Gao, Shizhou Huang, Junling Zhuang, Advitya Garg, Mohammad Hasibur Rahman, Mengliang Zhang, Qin Qin, Yu Yu


Abstract
Multimodal agents are increasingly evaluated on their ability to search the web, invoke tools, and solve complex tasks autonomously. Yet no existing benchmark systematically evaluates the capability of autonomously searching, parsing, and extracting precise answers from multimodal raw media files as a unified, end-to-end agentic task. We introduce RDQA - Raw Data Question Answering, a benchmark of 1,350 questions across three source modalities (document, video, audio), and 20 real-world task scenarios, where every answer is designed to require source access rather than model knowledge alone. RDQA provides capability-stratified evaluation through 9 capability families organized by modality and cognitive complexity, and introduces the Parametric Leakage Rate (PLR), a process-aware metric that flags correct answers produced without genuine evidence retrieval. We evaluate 12 agent systems spanning 6 backbone models and 2 scaffoldings. Our results show that the the best generic agent reaches only 24.0% adjusted accuracy, while a process-aware baseline (RDQA-Skill) reaches 41.1%. PLR reaches as high as 96.0%, indicating that many ostensibly correct answers are not grounded in retrieved evidence. We release the full dataset, evaluation framework, and a baseline to support future research.
Anthology ID:
2026.emnlp-main.1855
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:
42175–42194
Language:
URL:
https://aclanthology.org/2026.emnlp-main.1855/
DOI:
Bibkey:
Cite (ACL):
Wentao Gao, Shizhou Huang, Junling Zhuang, Advitya Garg, Mohammad Hasibur Rahman, Mengliang Zhang, Qin Qin, and Yu Yu. 2026. Can Your Agent Read the Source Faithfully? Benchmarking MLLM Agents on Source-Grounded Multimodal Retrieval. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 42175–42194, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Can Your Agent Read the Source Faithfully? Benchmarking MLLM Agents on Source-Grounded Multimodal Retrieval (Gao et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.1855.pdf