Reproduce. Report. Repair.
Good bug reports get good fixes. Whether you're telling the agent or a developer, give it the same four things.
01
Reproduce
Make it happen again on purpose. Note the exact steps.
02
Collect
The full error, the console, the logs, a screenshot.
03
Report
What you did, what you expected, what you got.
04
Verify
Repeat the steps after the fix, then add a test.
Steps. Expected. Actual. Full error.