I would have to assume that someone has removed them.
If the code was removed for the title and description you'll need to add it back in.
This page might be of interest to help you change the code for theme.liquid (assuming that's the file with the code) back to what it was earlier.
Before you roll back and of the template file be sure to make a copy of that theme. If you're not 100% sure what to do here you might want to hire in help. It's hard to give you mich direction here since the forum members can't see the entire code of your theme.
Rolling back may also remove other customisations so you want to be very sure you want to do this. One you roll back, you can not step forward (or roll forward).
In my experience, I have found this app more reliable with google grabbing the keywords that you want to display...