Call for scene-shifting? It's tea break! (11)
I believe the answer is:
necessitate
'call for' is the definition.
('necessitate' can be a synonym of 'call for')
'scene-shifting? it's tea break' is the wordplay.
'shifting?' is an anagram indicator.
'break' is an anagram indicator.
'scene' anagrammed gives 'neces'.
'its'+'tea'='itstea'
'itstea' anagrammed gives 'sitate'.
'neces'+'sitate'='NECESSITATE'
(Other definitions for necessitate that I've seen before include "required" , "Render unavoidable" , "Compel" , "Require, oblige" , "Entail" .)