Sec. 11. (a) "Agency" means any authority, board, bureau, commission, committee, department, division, hospital, military body, or other instrumentality of:
(1) the state, a county, a township, a city, a town, a separate municipal corporation, a special taxing district, or a public corporation; or
(2) a state assisted college or state assisted university.
(b) The term does not include any part of the legislative department or the judicial department of state government.