The Federal Reserve controls a very short-term interest rate - the overnight federal funds rate - but, as you know, theory and empirical evidence make clear that longer-term rates matter most for the economy. Those longer-term rates, in turn, reflect expectations of future short-term rates, as well as premiums for uncertainty.
If the monetary authority can be clearer about what it is doing now and what it plans to do - not in the sense of setting future moves in stone, but rather in terms of explaining risks that might influence future policy - then market participants can improve their expectations of future short rates.