Designing Agent Architectures
Architecture Choices
Common Patterns
Many agent systems can be described as combinations of planner-executor loops, tool-augmented workflows, retrieval-augmented memory, and critique or review modules. The best architecture depends on task complexity, latency, risk, and cost.
Architecture Patterns
| Pattern | Best For |
|---|---|
| Planner-executor | Long tasks that need sequencing |
| Tool-augmented workflow | Tasks requiring external data or actions |
| Retrieval-augmented agent | Tasks needing relevant stored knowledge |
| Debate or critique loop | Tasks benefiting from review and error detection |
Choosing the Right Design
Use the simplest design that can meet the requirement. Complexity should be added only when it improves reliability, speed, safety, or maintainability.
Architecture Heuristic
If a task is repetitive and well-defined, favor structure. If it is uncertain and exploratory, favor stronger planning, memory, and verification.
Which architecture is best matched to tasks requiring repeated tool calls and step-by-step progress?
Planner-executor designs are built for sequenced multi-step work.
Correct answer: Planner-executor
What is the main design principle when choosing agent architecture?
Overly complex systems are harder to debug and maintain.
Correct answer: Use the simplest architecture that satisfies the task requirements.
Simple vs Complex Systems
Simple System
- Faster to build
- Easier to test
- May be less capable on long tasks
Complex System
- More flexible
- Can handle richer workflows
- Harder to secure and debug
Which factor should most influence architecture choice?
Agent architecture should be selected based on functional constraints.
Correct answer: Task complexity, latency, risk, and cost