Workflow vs Agent: Anthropic's Distinction
Workflow = predefined sequential steps. Agent = LLM chooses its own steps. Use each in its place.
Anthropic's pivotal observation: for most use cases, 'workflow' is enough — 'agent' is overkill.
Workflow: developer codes sequential steps. LLM performs a specific subtask per step (classify, summarize, translate). Flow is fixed, deterministic. Example: customer email → category → priority → automated reply draft → admin approval.
Agent: the LLM decides itself which step to take next, revises the plan as needed, chooses when to exit the loop. More flexible, more expensive, less predictable.
Decision matrix:
- Fixed + repeatable steps → workflow
- Variable + research-driven steps → agent
- High cost of error + audit needed → workflow (with HITL)
- Creativity & flexibility critical → agent
Practical: 80% of use cases = workflow, 20% = agent. When you do choose agent, commit to agentic (planning + memory + tool chains).
What you'll gain
Looking at any use case, you can decide workflow vs agent in 5 seconds.