Longman Dictionary of Contemporary English
full marks
noun
EXAMPLES FROM CORPUS
▪ John gets full marks for providing excellent experience and guidance.
▪ None of them got full marks.
▪ Only one in six adults scored full marks in a test of six familiar words.
▪ So, not a wigging, you see, but not full marks either.
▪ Well done Ralph, and full marks Henry.
▪ Well, full marks for courage, Major.
▪ You had to give the woman full marks for persistence.
Wiktionary
full marks
interj. To exclaim complete satisfaction with someone's efforts. n. 1 the maximum marks obtainable in an exam or test. 2 (context idiomatic by extension English) To say you think someone is correct in what they say.
Usage examples of "full marks".
Digging in one pocket of his jacket he wore, Scar-face dropped two full marks and two half marks, all weaver stamped, into Tagetarl's hand.