1) Demanding 2) Picky 3) Severe 1) Extortionate 2) Fastidious 3) Finicky 4) Fussy 5) Harsh 6) Making rigorous demands 7) Meticulous 8) Picky 9) Requiring precise accuracy 10) Scrupulous 11) Stringent 12) Tough old deputy 13) With no margin for error 
• (a.) Oppressive or unreasonably severe in making demands or requiring the exact fulfillment of obligations; harsh; severe. • (p. pr. & vb. n.) of Exact
Ex·act'ing adjective Oppressive or unreasonably severe in making demands or requiring the exact fulfillment of obligations; harsh; severe. 'A temper so exacting .' T. Arnold -- 
adjective having complicated nutritional requirements; especially growing only in special artificial cultures; `fastidious microorganisms`; `certain highly specialized xerophytes are extremely exacting in their requirements`
rigid or severe in demands or requirements: an exacting teacher. · requiring close application or attention: an exacting task. · given to or characterized by exaction; extortionate.
severe and unremitting in making demands