Meta tag of redesign website
 

Hi
My Old website is Ranked for Many 2 Phase keywords, in that website there is Very Less optimization has been done as per the standard practice guide of Title tag 56 chars and and even not installed meta tag for every page of website.

Despite of that search engine crawl metatag from relevant content of Home pages, now we will go to change the website home page, and old home page content will not anymore in new website only in home page.
So Question is
Did I to need create the Metatag according to best onpage practice or put SERP metatag which is display in Search Engine result page(SERP) , which is already rank well.

Changing the meta tags might your keyword rankings and you might see a huge dip in the keyword rankings. What if you couldn't achieve those keyword rankings and traffic again ever? Would recommend not to change the onpage unless it's necessary.

If your old meta is good for your new page service then you can continue to that otherwise you can change or update that.

thanks