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09 · Agents, Tools & MCP

What Is Human in the Loop?

Human in the Loop means placing human review, approval, or intervention at selected points in an AI workflow.

The AI can still do most of the work, while humans retain control over important decisions or actions.

Human review is a control gate

A human does not need to approve every step. Review is inserted where judgment, authorization, or risk management matters.

InputUSER GOAL
↓
WorkAGENT WORKS
↓
ProposalPROPOSED ACTION
↓
GateDOES THIS REQUIRE APPROVAL?
NO → EXECUTEYES → HUMAN REVIEW → APPROVE / REJECT / MODIFY → CONTINUE

Human review is a control gate, not a requirement for every step.

Think of it like...

An employee preparing a payment request.

Employee

Collects information and prepares the action.

Manager

Approves a sensitive payment before it is sent.

Mapping: Agent → prepares / recommends. Human → approves a selected high-impact action.

One real example · Customer refund

An AI agent can read the order, check the refund policy, calculate the refund, and prepare the refund action.

Read order→Check policy→Calculate refund→REFUND > $500→HUMAN APPROVAL REQUIRED→Approve or reject→Agent continues

Where human review helps

Financial actions

Payments · refunds

Data changes

Delete · overwrite

External communication

Send email · publish

Sensitive access

Private systems · personal data

Ambiguous cases

Low confidence · exceptions

Human in the Loop vs Manual Workflow

Manual workflow

Human performs most steps.

Human in the Loop

AI performs many steps. Human intervenes at selected control points.

Human in the Loop ≠ human does everything.

Human Approval vs Validation

Validation

System checks rules automatically.
Example: refund amount ≤ policy limit.

Human approval

A person explicitly reviews or authorizes.
Example: finance manager approves refund.

HITL vs a more autonomous flow

HITL

Selected actions require review.

More autonomous flow

More actions execute without review.

This is a spectrum, not a binary choice.

Connection to the Agent Loop

OBSERVE → DECIDE → PROPOSE ACTION → HUMAN GATE → ACT → OBSERVE RESULT ↺

Human approval can interrupt or redirect the agent loop.

What it is NOT

Human in the Loop≠Manual Everything
Human Approval≠Validation
Human Review≠Every AI Request
Human in the Loop≠No Automation

Remember this

Human in the Loop adds human control at selected points where judgment, approval, or risk management matters.

Video

Video

not available yet

A Human in the Loop explainer video will be added here when a real video file is available.

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