The meta description and the title are important so you should make sure each page of your site has an unique and relevant title and description.
What's this NEW meta description? What do you mean? If your idea is to use DIFFERENT title and description in every inner page in your website, then yes, this is a good idea!
It shows up as a site summary in many search engines so it has to be carefully designed. It should be a maximum of 170 to 200 words and should be descriptive yet concise and catchy. This is what makes search bot’s task easy in categorizing a website according to the keywords and also lets users see the relevancy of a webpage in relation to their query. SO YES, IT´S HELPFUL