Only one side is quite as it should be (4,5)
I believe the answer is:
'quite as it should be' is the definition.
I can't judge whether this defines the answer.
'only one side' is the wordplay.
'only' becomes 'just' (synonyms).
'one side' becomes 'right' (I've seen this before).
'is' is the link.
Can you help me to learn more?
(Other definitions for just right that I've seen before include "Perfect", "Exactly what was required".)