In past Google’s search result META description length was 150 characters. But now the limit is changed to 160 characters in 2016.
Before the search results width was 520px. And now the minimum or maximum length of width also changed to 600px. That’s why the lengths of META Descriptions and Titles length changed.
In some times the minimum and maximum lengths are 160 to 172 characters may be supports.
But the best optimization previous description length is 150 characters. and now new length is 160 characters.