Is "Please be reminded to ..." a valid construction?

I received an email today with the following sentence:

Please be reminded to bring your basketball gear in.

He was subsequently made fun of by a co-worker:

'Please be reminded' - Will you be doing the reminding, or should I expect somebody else to be reminding me?

I am wondering if:

1. the original sentence is valid and unambiguous, or if
2. the interpretation made by his co-worker is valid due to ambiguity in the semantic meaning of the original sentence.

Solution 1:

The sentence is grammatical: a passive construction does not necessarily need an agent. That said, as others have commented, it’s probably not the most effective way of putting it.

Solution 2:

I agree with your coworker: the phrasing is slightly pretentious and obviously imprecise. I would prefer "I would like to remind you to...", which moves it from the passive voice to the active, or simply "please bring your basketball gear with you."

Solution 3:

This is a standard formal construction used in academic conferences and elsewhere. The extreme formality is intended to remove responsibility for the act of "reminding" from the Master of Ceremonies, who presumably is of far lower status than the speakers, moderators, or participants in the conference.