This makes work easier when you create or edit many products one after the other.
This tool shows you the characters that are still free while you are still typing!
For the categories: Category name, category heading, meta title, meta description, meta keywords
and for the products : Item name, manufacturer link, additional terms for the search, Meta Title, Meta Description, Meta Keywords.
Especially when you are trying to be creative (Meta Description), it is a great relief to be able to see out of the corner of your eye how much you are still allowed to type!
If there are no more characters "free" you will be stopped by the tool - you cannot accidentally type too much.