Reading up it seems like there's complete free reign to enter what you want in the meta description and they are not considered a direct ranking signal However I have added contact numbers to the meta descriptions for around 20 reasonably high ranking pages for my company and it seems to have had a negative effect (taken screen grabs and previous rankings) More strangely when you 'inspect' the page the meta description features the desired number yet when you find the page in the serps the meta description just does not feature the number (page has been cached and the description does not carry on) I'm wondering whether such direct changes are seen as spam and therefore negative to the page?