How to set data from db A to db B

Hello bubblers,

I need your help please. I have two db and I need to set for Items in db A same description of items in db B but only if item names from db A and are identical with item names from db B.

See below what I am doing now and is not working. Any other suggestion?

I have also made a diagram trying to explain better of what I am trying to achieve here: