I can start:
He has withdrawn ashamed- he withdrew
An angel appears to him and foretells him the birth of a girl.- You jump to the present and back to the past in the next sentence- I stick to the present
The commission of this group and the three following ones dated- here I would use 'dates'
A shepherd sitting on the foreground plays the bagpipe- bagpipes
a second shepherd carries at the belt shearing tools- carries shearing tools on his belt