AI Agents
AI Agents are systems that go beyond generating text. Instead of only predicting the next token, they take actions, make decisions, and complete tasks step by step to achieve a goal.
This is the key shift:
- Generative AI → predicts next word
- AI Agents → decide next action
Generative AI vs AI Agents
Generative AI (Next Token Prediction)
Generative AI models (LLMs) work by predicting the next token in a sequence.
Example:
Input: "The capital of France is"
Output: "Paris"
How it works:
- Break input into tokens
- Predict probability of next token
- Select most likely token
- Repeat until response is complete
Limitations:
- No real goal awareness
- Cannot take actions
- Stateless (each prompt is isolated)
- Can hallucinate
AI Agents (Step-by-Step Decision Making)
AI Agents operate in a loop where they:
- Understand a goal
- Plan steps
- Take actions (tools/APIs)
- Observe results
- Adjust and repeat
Example goal:
"Find the best laptop under $1000 and summarize top 3 options"
Agent behavior:
- Search web
- Compare products
- Summarize results
- Deliver final answer
Core Difference
| Aspect | Generative AI | AI Agents |
|---|---|---|
| Core Function | Next token prediction | Action selection |
| Goal Awareness | No | Yes |
| Memory | Limited | Can maintain state |
| Tool Usage | No | Yes |
| Reliability | Lower | Higher (with iteration) |
Agent Loop
AI Agents follow a reasoning loop:
Goal → Plan → Act → Observe → Reflect → Repeat
This loop allows agents to improve results over time instead of generating a single response.
How Agents Use LLMs
Important:
Agents still use LLMs internally.
But instead of using them once, they use them repeatedly to:
- Decide next step
- Choose tools
- Evaluate results
LLM becomes the brain, agent becomes the system.
Example: Simple Agent
def agent(task):
if "weather" in task:
return "Calling weather API..."
elif "news" in task:
return "Fetching latest news..."
else:
return "Planning next step..."
print(agent("weather today"))
Real-World Use Cases
- Research assistants
- Coding agents
- Workflow automation
- Customer support automation
- Data analysis pipelines
Why Agents Are More Reliable
Generative AI:
- Produces one-shot answers
- No verification
- Can hallucinate
Agents:
- Break problems into steps
- Validate intermediate results
- Retry if needed
- Use external data sources
This makes agents better for real-world applications.
Agent + RAG + Tools
Modern agents combine multiple systems:
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User Request
↓
Agent
↓
LLM (reasoning)
↓
RAG (knowledge retrieval)
↓
Tools / APIs
↓
Final Output
Types of Agents
- Reactive Agents → respond immediately
- Planning Agents → create multi-step plans
- Tool-Using Agents → interact with APIs
- Autonomous Agents → operate independently
Common Frameworks
- LangChain Agents
- AutoGen
- CrewAI
- Semantic Kernel