TCFDNav: Benchmarking Index-Guided Navigation from Annual Reports

When a PDF provides a human-readable index, its mapping table should be used to locate information. Disclosure indexes based on the Task Force on Climate-related Financial Disclosures (TCFD) provide a representative example. However, existing approaches largely rely on similarity-based retrieval, while index-guided navigation remains underexplored. We therefore introduce TCFDNav, a benchmark for evaluating the recovery and execution of index-declared navigation relations in the TCFD setting. Rather than focusing on an isolated step, we address the complete navigation process, from an input annual report to the TCFD-related pages referenced by its index. Starting with 100 UK annual reports and extending to 17 external PDFs, we construct an annotated resource covering the full navigation chain. To support benchmark evaluation, we propose a three-stage reference framework that discovers complete indexes, recovers their declared relations, and resolves target addresses to produce traceable navigation maps. From a deployment perspective, Qwen3.5-27B performs competitively with leading proprietary models, showing the practical potential of open-weight models for this task.