Improving Outreach Agent's Google Sheet for New Entries Efficiency

For the outreach agent that reviews a google sheet for new lines added - is there a better way that anyone has found to set this up? The “new line added” part doesn’t seem to be very reliable. It breaks pretty often and I have to start all over with a new spreadsheet which defeats the purpose of this being automated whenever I add a new contact. Has anyone tried having to search for a new email address daily instead? Or any other good options?