In the banking and finance sectors, members of the business units focused on Trend and Risk Analysis daily process internal and external visually-rich documents including text, images, and tables. Given a facet (i.e., topic) of interest, they are particularly interested in retrieving the top trending keywords related to it and then use them to annotate the most relevant document elements (e.g., text paragraphs, images or tables). In this paper, we explore the use of both open-source and proprietary Large Language Models to automatically generate lists of facet-relevant keywords, automatically produce free-text descriptions of both keywords and multimedia document content, and then annotate documents by leveraging textual similarity approaches. The preliminary results, achieved on English and Italian documents, show that OpenAI GPT-4 achieves superior performance in keyword description generation and multimedia content annotation, while the open-source Meta AI Llama2 model turns out to be highly competitive in generating additional keywords.