This homework was done by Vasya at school.
Or
This homework was done at school by Vasya.
Are both sentences grammatical? Is it okay to put the adverbial at school either before or after the agent Vasya? (Leaving out the obivous issue of the shift of focus).
I've read that adverbs of manner, place and time usually go in end position, but here the adverbial can possibly be used in either of the two slots.
One person, however, said that her teacher had told her to always place the agent at the very end of a passive sentence (as in my example sentence 2). That made me curious.
Which of the two sentences will look more natural to the native speaker?