My 5.0 version of Lightroom 5 doesn't seem to have the Painter tool on the Library Module. The viewer modes does not have an option for the Painter tool. Would sure help to handle my keywording.
The Tool bar is not actually missing on the library module but it sure did disappear with the 't' . Have now got the tool bar back and, as before, I find the far right hand side of the tool bar does not have that choice of selecting 'painter tool'. It starts with 'sorting' and finishes with 'Grid overlay'.