A chatbot is a good fit when the user does not know what to ask for or when the answer depends on many variables. It is a bad fit for a simple form that has three fields. Use it to guide, not to replace clear UI.

Keep the conversation bounded. Give the bot a clear role, a small set of actions it can take, and an escape hatch to a human or a form. The more freedom you give an AI, the more ways it can go off-script.