A chatbot is enough when the job is mainly conversational: answer a bounded set of questions, guide a user through known choices, collect information, or route a request. An agent becomes useful when the system must pursue a goal across several steps, inspect changing state, use tools, and decide what to do next within defined limits.
Choose the simplest system that completes the work
A reliable FAQ assistant with good retrieval can create more value than an autonomous agent attached to every business system. Start by asking whether the user needs an answer, a recommendation, or an action. Answers usually need retrieval. Recommendations need evidence and constraints. Actions need authentication, permission checks, task state, and recovery.
| Requirement | Likely starting point |
|---|---|
| Answer from approved documents | RAG chatbot |
| Collect details and hand off | Guided chatbot with workflow integration |
| Check several systems and prepare a decision | Tool-using agent with review |
| Execute a multi-step process | Agent workflow with durable state and controls |
Look for the hidden operating cost
Every additional tool creates permission, testing, logging, and failure-handling work. Autonomous planning also increases the number of paths the team must evaluate. If a deterministic workflow can handle most cases, use it and reserve model judgement for the genuinely variable step.
A useful design often combines both approaches: a retrieval assistant handles questions, a structured workflow collects required details, and an agent is invoked only when a case needs reasoning across sources or tools.
Use evidence to expand
Measure unresolved questions, handoff reasons, repetitive manual actions, and cases where users abandon the process. These observations show where more autonomy may help. The RAG chatbot versus agent comparison, build-versus-buy guide, and agent cost guide provide deeper decision criteria.
The right choice is not the system with the most autonomy. It is the smallest system that completes the intended work reliably and gives people a clear path when it cannot.