Course module

Agentic Systems

An agent is not a chatbot with tools.

4 min read• Markdown-first learning note

An agent is not a chatbot with tools.

An agentic system is a workflow where the system can decide the next step, call tools, observe results, and continue until a goal is reached or a boundary is hit.

The hard part is not making the agent act.

The hard part is making the action safe, observable, reversible, and useful.

Scenario: support workflow assistant

Imagine an assistant for a SaaS support team.

A user says:

A customer says they were charged twice. Check the account and prepare a refund if needed.

This is not a normal Q&A problem.

The assistant may need to:

  • inspect customer account details
  • check invoices
  • compare payment events
  • draft a support reply
  • prepare refund action
  • ask for approval before executing
  • log every step

Now the system is not only answering. It is acting.

Bad agent design

A weak design says:

This is dangerous because the system has no clear boundary.

Common mistakes:

  • giving the agent too many tools
  • no risk classification
  • no human approval for money movement
  • no trace of why a tool was called
  • no retry or rollback plan
  • no timeout or stopping condition
  • memory mixed with audit logs

Rule

The more power an agent has, the more boring and explicit the control layer should be.

Better agent design

A better design separates reasoning from permission.

Rendering diagram...

Action risk levels

ActionRiskControl
Search docsLowLog only
Read account statusMediumPermission check
Draft refund replyMediumReview suggested
Execute refundHighHuman approval required
Delete accountCriticalUsually block

This table is more important than the model choice.

Memory design

Do not put all memory in one bucket.

Use different memory types:

Memory typeExamplePurpose
Short-term contextCurrent ticket detailsSolve current task
User preferenceCustomer prefers emailPersonalize response
Tool stateRefund check completedAvoid repeating steps
Audit historyTool calls and approvalsDebug and compliance
Long-term learningCommon failure categoriesImprove future workflow

A common beginner mistake is to mix audit history and preference memory. That creates confusing and unsafe behavior.

What to log

For every agent step, log:

  • original goal
  • planned next step
  • selected tool
  • input to tool
  • output from tool
  • risk level
  • approval status
  • model used
  • cost and latency
  • final result

If you cannot inspect a step, you cannot trust it.

Evaluation signals

SignalQuestionFailure example
Task successDid the agent complete the goal?It found invoices but did not prepare reply
Tool correctnessDid it call the right tool?It searched docs instead of checking billing
Boundary safetyDid it ask approval for high-risk action?Refund executed without review
Drift controlDid it stay on task?It started explaining billing policy instead
Trace qualityCan a human inspect the path?Missing tool inputs or outputs

Practice exercise

Design an agent for one workflow:

  • pharmacy order support
  • college admission inquiry
  • refund processing
  • internal IT helpdesk

Write:

  1. Goal
  2. Allowed tools
  3. Blocked actions
  4. Actions requiring approval
  5. Memory types
  6. Logs and traces
  7. Evaluation signals

Summary

Agents are useful when a workflow needs reasoning plus action.

But autonomy without boundaries is not engineering.

A good agentic system defines what the system can do, what it cannot do, what needs approval, what gets logged, and how failures are evaluated.