One answers questions, the other does work. A practical test to choose — and when the honest answer is a good chatbot.
A chatbot answers questions from a script or your documents. An agent takes action: it reads the request, checks your systems, decides the next step and does it — booking, updating, notifying — then reports back.
Pick the chatbot when the job is informing: opening hours, prices, policies, order status. It is cheaper, safer and easier to maintain, and for many businesses it is all they need.
Pick the agent when the job is doing: qualifying a lead and booking the call, chasing an unpaid invoice, preparing Monday's report from five sources. If nobody must touch it between trigger and result, it is agent work.
Avoid the two traps: an agent for a problem a page could solve, and a chatbot drowning in tasks that need actions. Both cost money and teach customers to distrust the automation.
Start from the outcome, not the technology: what should happen without a person, what must always reach one, and how you will measure it in the first month.