Does size matters or not for Google in terms of meta tags length?
The length of the meta title and meta description shouldn’t exceed the allowed amount of characters, otherwise they’ll be cut short and users won’t see the endings on the search engine results page.
Recently Google doubled the length of snippets from 160 to 320 characters. This gives you more space to describe in more detail what your page is about. However, this doesn’t mean that you should use the maximum number of words or rewrite your previous shorter description tags. Just make sure you use your main keywords wisely to let users quickly estimate how relevant your page content is to what they are looking for. Try at the same time to interest and intrigue users. By the way, Google will not always use your description tags. Instead it extracts a snippet from the page content itself up to 320 characters, so you’ll enjoy the benefits of the expanded snippet without doing anything.