# M01-L04 exercise — Write an engineering brief

**Start:** M01-L03 and Chapter 3 original reporting resources.

Create `task-brief.md` to request a summary counting valid and invalid records in the Chapter 3 original reporting fixture. First inspect and count the records independently.

Include goal, checkpoint and filename, current state, relevant input, constraints, requested summary format, and acceptance criteria. Require preserved input, correct total and validity split, synthetic labeling, and separation of proposed commands from actual results. Submit the brief with the relevant input or review the supplied original alternative. Save a criterion-by-criterion review and one correction if needed.