Not every workflow that uses an LLM is an AI agent. The important difference is what happens when the system has to decide what to do next.
AI agents are everywhere right now.
But so is the word agent.
A chatbot with tool calling is called an agent.
A RAG application is called an agent.
An LLM inside a predefined workflow is called an agent.
This creates a useful engineering question:
Where does an AI-powered workflow end and an AI agent begin?
Start with the simplest distinction
Consider this workflow:
User Request
↓
LLM
↓
Extract Information
↓
Call API
↓
Return Result
There's AI involved, but the execution path is predetermined.
The developer decides:
- what happens first
- which tool gets called
- what happens afterward
- when the workflow ends
The LLM might make a decision inside one step, but the overall system doesn't necessarily decide its own next step.
Now compare that with:
Goal
↓
Reason
↓
Choose Action
↓
Use Tool
↓
Observe Result
↓
Adapt
↓
Choose Next Action
↓
Repeat / Stop
Here, the next action depends on what the system discovers.
That's where things become much more agentic.
The question I keep coming back to
Who decides what happens next?
This is more useful than asking whether a system "uses AI."
Imagine an incident-management system.
A traditional workflow might look like:
Incident detected
↓
Classify incident
↓
Create ticket
↓
Notify engineer
↓
End
Everything is predefined.
An agentic system might instead:
Incident detected
↓
Investigate
↓
Check logs
↓
Observe unusual errors
↓
Check recent deployments
↓
Find suspicious deployment
↓
Evaluate remediation
↓
Request approval
↓
Execute
↓
Verify recovery
The important part isn't simply that an LLM is involved.
The important part is that the system's next action depends on what it observes.
Tool calling doesn't automatically make an agent
This is an easy mistake to make.
Consider:
Question
↓
LLM
↓
Weather API
↓
Answer
The model used a tool.
But that doesn't necessarily make it an agent.
Now consider:
Goal
↓
Find customer
↓
Review previous conversations
↓
Check open tickets
↓
Identify unresolved issue
↓
Search documentation
↓
Find missing information
↓
Search another source
↓
Prepare briefing
Here, intermediate results influence what the system does next.
That's a much stronger case for agentic behavior.
Planning isn't enough either
Another common definition is:
"If an AI can create a plan, it's an agent."
Not necessarily.
A system could generate:
1. Search database
2. Analyze results
3. Send email
and then execute those exact steps regardless of what happens.
A more agentic system can change the plan:
Create plan
↓
Execute
↓
Observe result
↓
Plan doesn't work
↓
Generate alternative
↓
Execute alternative
↓
Evaluate
The interesting capability isn't just planning.
It's replanning based on observations.
Think in terms of a feedback loop
A useful mental model is:
Reason → Act → Observe → Adapt
↑ |
└───────┘
Instead of:
Prompt → Generate → Finish
Suppose you ask an agent:
Find the cause of this production error.
It might:
- Inspect logs.
- Find an unusual error.
- Check recent deployments.
- Identify a possible correlation.
- Investigate the deployment.
- Discover that the hypothesis doesn't explain the issue.
- Change direction.
- Investigate another possibility.
- Produce a conclusion.
The environment is feeding information back into the decision process.
That's what makes the architecture interesting.
What about memory?
Memory is useful, but it isn't what defines an agent.
A support application might remember:
- previous conversations
- customer preferences
- account information
- past interactions
But if it still follows a fixed workflow, memory doesn't automatically make it an agent.
Memory is a capability.
Agency is about decision-making and action.
Agents still need boundaries
There's another assumption worth challenging:
More autonomy = better agent.
In production, unlimited autonomy can be dangerous.
Imagine an agent with access to:
- production databases
- customer records
- payment systems
- cloud infrastructure
- deployment pipelines
It may be capable of taking all those actions.
That doesn't mean it should be allowed to.
A production architecture might instead look like:
Goal
↓
LLM Reasoning
↓
Policy Check
↓
Permission Check
↓
Tool Execution
↓
Observe Result
↓
Next Decision
Some actions can be automatic.
Some should require human approval.
Some should be blocked.
This is where agentic AI becomes an engineering problem, not just an LLM problem.
Probabilistic reasoning vs deterministic execution
One architecture pattern I find particularly useful is separating reasoning from execution.
LLMs are probabilistic.
Production systems often need predictable behavior.
So you can separate the two:
┌──────────────────────┐
│ Goal / Context │
└──────────┬───────────┘
↓
┌──────────────────────┐
│ LLM Reasoning │
└──────────┬───────────┘
↓
┌──────────────────────┐
│ Policy & Validation │
└──────────┬───────────┘
↓
┌──────────────────────┐
│ Execution Layer │
└──────────┬───────────┘
↓
┌──────────────────────┐
│ External Systems │
└──────────┬───────────┘
↓
Observe
│
└────→ Next Decision
The model can determine what it thinks should happen.
The execution layer determines what is actually allowed to happen.
That separation becomes increasingly important when agents interact with real systems.
So, what makes something an agent?
There's no single definition everyone agrees on.
But I usually look for these capabilities:
1. Goal-directed behavior
The system is working toward an outcome.
2. Action selection
It can choose between possible actions.
3. Tool use
It can interact with external systems.
4. Observation
It can see what happened after taking an action.
5. Adaptation
It can change its approach based on the result.
6. State
It maintains enough context to pursue the goal across multiple steps.
7. Bounded autonomy
Its actions are constrained by permissions, policies, budgets, and other controls.
The more of these capabilities a system has, the stronger the case for calling it an AI agent.
Here's a practical test
Instead of asking:
Does this application use an LLM?
Ask:
What happens when the expected path breaks?
If the answer is:
"It follows the next predefined step."
You're probably looking at automation.
If the answer is:
"It evaluates the result, considers alternatives, and decides what to do next within its permitted boundaries."
You're much closer to an agent.
Do we actually need an agent?
This might be the most important question.
Not every problem needs one.
If a process is:
- predictable
- deterministic
- well-defined
- easy to express as a sequence
then a traditional workflow may be the better architecture.
Agents become more useful when:
- the environment is dynamic
- the path isn't known beforehand
- multiple actions are possible
- results influence future decisions
- unexpected outcomes need to be handled
The goal shouldn't be to make everything agentic.
Use the architecture that matches the problem.
How we're thinking about it at Nuroen
At Nuroen, we're interested in the engineering layer between AI reasoning and real-world execution.
The challenge isn't simply putting an LLM inside a workflow and calling it an agent.
It's building systems where agents can reason and act while the execution environment provides meaningful controls around those actions.
That means thinking about:
- Tool permissions
- Policy enforcement
- Human-in-the-loop actions
- Execution limits
- Observability
- Auditability
- Controlled autonomy
In short:
Let the model reason. Let the system govern execution.
That's a more useful foundation for production agentic systems than simply adding the word agent to an AI workflow.
Final thought
Not every AI-powered workflow needs to be an agent.
And not every agent needs unlimited autonomy.
Sometimes a deterministic workflow with an LLM handling one difficult step is exactly the right solution.
Other problems genuinely require a system that can:
Reason → Act → Observe → Adapt.
The important thing is to design for the problem—not the buzzword.
What do you think is the minimum capability an AI system needs before you'd call it an agent?
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