HEX: Agentic Framework for Closed-domain Web Tables Generation

Existing WebListQA frameworks mostly treat list-based web queries as an entity extraction task, failing when answers require multi-attribute information of entities. We formalize this limitation as comprehensive retrieval, a high-recall task of synthesizing structured tables from web sources. While recent agentic retrieval frameworks can autonomously browse the web to retrieve information, they lack effective query reformulation and structured boundaries necessary to aggregate web entities into a comprehensive table. To address these limitations, we introduce HEX, a six-state agentic framework that leverages LLM-based decision making within state-machine boundaries. HEX ensures exhaustive retrieval of entities and their attributes to generate a comprehensive web table. Evaluating HEX against state-of-the-art baselines across three healthcare domain tasks demonstrate that HEX improves entity recall from 10\