Standards of service right for inclusion by agents (8)
I believe the answer is:
criteria
'standards' is the definition.
('criterion' can be a synonym of 'standard')
'service right for inclusion by agents' is the wordplay.
'service' becomes 'rite' (a religious service).
'right' becomes 'r' (common abbreviation).
'for inclusion by' is an insertion indicator.
'agents' becomes 'CIA' (Central Intelligence Agency).
'rite'+'r'='riter'
'riter' placed into 'cia' is 'CRITERIA'.
'of' is the link.
(Other definitions for criteria that I've seen before include "Standards on which to base judgments" , "Principles on which to base a judgement" , "set of rules" , "Principles for judging" , "Principles for decision" .)