working agreement vs agreement

working agreement and agreement both are nouns.

Word	Noun	Adjective	Verb	Adverb
working agreement	Yes	No	No	No
agreement	Yes	No	No	No

As nouns, agreement is a hypernym of working agreement; that is, agreement is a word with a broader meaning than working agreement:

Other hypernyms of working agreement include understanding.

working agreement (noun)	agreement (noun)
an informal agreement to work together	compatibility of observations
	the thing arranged or agreed to
	the verbal act of agreeing
	the statement (oral or written) of an exchange of promises
	the determination of grammatical inflection on the basis of word relations
	harmony of people's opinions or actions or characters