Rosh Hashana 28b - mitzvos require kavana

The gemara tries to prove that mitzvos need kavana from the fact that we say the mashmiah (blower 0r reader) must have kavana. Tosafos questions that perhaps the kavana we are requiring for the mashmiah is kavana to be motzi the listener. The Turei Even points out that this seems to indicate that even if we hold mitzvos don't need kavana to be yotzei; in a case where someone is being motzi you, he must still have intent to be motzi you. This is what Tosafos means - that had we interpreted the kavana required by mashmiah as kavana to be motzi the listener, then we would not have a proof from here that mitzvos need kavana. This seems to make sense, since without the mashmiah intending to be motzi the listener, there is really nothing connecting them.