We have a couple of systems at work that incorporate LLMs. There are a bunch of RAG chatbots for large documentation collections and a bunch of extract-info-from-email bots. I would none of these call an agent. The one thing that comes close to an agent is a very bot that can query a few different SQL and API data sources. Given a users text query, it decides on its own which tool(s) to use. It can also retry, or re-formulate its task. The agentic parts are mainly done in LangGrah.