Write them once, see how they will actually look, and get told before something gets cut off.
Google result
Shared link — Facebook, LinkedIn, X, Slack, WhatsApp
About the length warnings. Search engines truncate by pixel width, not by
character count, so no tool can promise an exact cut-off — a title of capitals and W's runs
out long before one made of i's and l's. The limits used here (about 60 characters for a
title, 155 for a description) are the practical thresholds where truncation becomes likely.
Treat them as a warning line, not a law.
The image matters more than the tags. A link with no og:image
is rendered by most platforms as a plain text line, and gets a fraction of the clicks.
1200×630 is the size every major platform accepts without cropping.