limit the post snippet in categories?

Do you mean like a post teaser plugin so it shwos only as many characters as you want it to on the page and then you click on it to read more?

yes exactly

https://dev.wp-plugins.org/wiki/PostTeaser

or https://guff.szub.net/2005/02/26/the-excerpt-reloaded/

(Presumably your theme has a category.php)