Only one side is quite as it should be (4,5)
I believe the answer is:
just right
'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).
'just'+'right'='JUST RIGHT'
'is' is the link.
Can you help me to learn more?
(Other definitions for just right that I've seen before include "Exactly what was required" , "Perfect" .)