Indictments are lists of charges; expecting them to be informative for questions other than “what is the defendant being charged with” is irrational. (And “what is the evidence supporting the charges” is a separate question.)
> All the other overt acts listed appear to have been carried out by his unnamed alleged co-conspirator alone.
A conspiracy charge only requires any of the conspirators to have taken an overt act in furtherance of the conspiracy.