Part 5: Planning & Reasoning¶
Overview¶
What makes an agent different from a chatbot? Reasoning and planning.
This section covers how agents think about problems, break them into steps, and adapt when things don't go as expected.
Core Concepts¶
| Concept | Description |
|---|---|
| Chain-of-Thought | Step-by-step reasoning visible in output |
| Tree-of-Thought | Exploring multiple reasoning branches |
| Decomposition | Breaking goals into sub-goals |
| Adaptation | Adjusting strategy based on results |
Chapter Map¶
Why This Matters¶
- Reliability: Explicit reasoning is debuggable
- Transparency: You can see why agent did something
- Quality: Better reasoning = better decisions
- Adaptability: Agents adjust to changing conditions
Key Insight¶
Reasoning is not thinking harder—it's thinking differently
A model using CoT on a hard problem might use 50% more tokens but get 30% more accurate answers. The extra tokens are spent on reasoning, not memorization.
Next: Start with Planning Fundamentals¶
Last Updated: August 9, 2026