Board resolution of 2 director pvt limited company

As per Sec.21 of Companies Act 2013, resolution can be  signed by any KMP (which includes an MD) or an officer of the company duly authorised by the Board.  Hence there is nothing illegal as such if the resolution is signed by MD.   However, as a matter of good corporate governance practice it is normally signed by some director other than the director in whose favour some authority is given.  Hence you can politely request the MD to get signature of second director also on the resolution which will give you a satisfaction and also avoid dispute that may arise among directors in future.  However, if it is difficult, you may just proceed with the existing resolution.  You can just check restrictions, if any, on the powers of the Board as per their Articles, a copy of which can be downloaded from MCA website after payment of fee.