Search results cut text off by pixel width, not characters, but character counts are a good guide.
Titles
Between 30 and 60 characters usually fits. Put the most important words first and the brand at the end.
Descriptions
Between 120 and 160 characters fits on desktop. Mobile cuts earlier, so lead with the point.
Google may rewrite them
Google sometimes shows different text if yours does not match the search. A clear, accurate description still wins most of the time.
A simple formula
Title: topic, benefit, brand. Description: what the page offers, who it is for, a reason to click.