CourseAgentic AI Engineer: The Complete Course · Module 6: Planning and Decomposition · part 36 of 97
Part 36 · Module 6: Planning and Decomposition

Lesson 2: Checking the work, not the agent's word

26 min read·13 Oct 2026
Module 6 · Lesson 2 · About 50 minutes · Needs: Lesson 1 (a plan of steps per request) and Module 5 (the agent loop)

The situation

It is Thursday 21 May 2026, week 6, the morning after the first unattended run in staging. Marta opens the simulator's payments view. The agent's report for R-1001 reads: "Return created and refund of $129.00 issued. Customer emailed." Aisha's inbox holds an email saying the same.

The refund is queued for Marta, as it should be: Aisha's robot vacuum, order 5521, is a $129.00 return, so it waits for finance. But the email and the report say it was issued, and everyone who read them believed it. This lesson makes "done" something BrightCart's systems confirm, not something the agent says.

AGENT'S REPORT THE SYSTEMS Return created one return, RET-001 Refund of $129.00 issued queued for Marta, not paid Customer emailed email claims a refund
Read against the systems, R-1001's report falls apart: the return exists (green), but the refund only waits for Marta while the report and email say it was issued (red). Amber marks what the model said.

The rest of this course is yours to keep

This course is bought on its own, once, and stays readable afterwards, including the parts added to it later.