---
name: principle-prove-it-works
description: "Apply before declaring a task done. Verify the changed behavior through the real artifact and report the observed result."
---

# Prove It Works

Before declaring a task done, exercise the behavior the user will rely on.

A successful build alone does not show that the changed behavior works.

## Apply it

1. Identify the behavior changed by this task.
2. Choose a direct check: run the CLI command, exercise the UI interaction,
   or inspect the generated document.
3. Run that check and compare the actual result with the expected result.
4. Report what you ran and what you observed.
5. If the check is blocked, state the blocker and what remains unverified.

Scale the check to the change. Prefer an existing command or workflow.
Do not invent a successful result or add unrelated checks.