stringent

binding demanding draconian exacting forceful harsh inflexible ironclad rigorous severe stiff strict tough

acrimonious brick-wall by the book by the numbers compelling confining convincing dead set on drawing dyed-in-the-wool hard hard-nosed iron-fisted picky poignant powerful rough set unpermissive valid

amenable calm easy easygoing facile flexible gentle kind lenient mild nice pliable pliant soft weak willing yielding

inexact tolerant