Full Idea
Tarski did not settle for a definition of truth, taking its adequacy for granted. Rather he proposed an adequacy criterion for evaluating the adequacy of definitions of truth. The criterion is his famous Convention T.
Gist of Idea
Tarski did not just aim at a definition; he also offered an adequacy criterion for any truth definition
Source
report of Alfred Tarski (The Concept of Truth for Formalized Languages [1933]) by Volker Halbach - Axiomatic Theories of Truth 3
Book Reference
Halbach,Volker: 'Axiomatic Theories of Truth' [CUP 2011], p.15
A Reaction
Convention T famously says the sentence is true if and only if a description of the sentence is equivalent to affirming the sentence. 'Snow is white' iff snow is white.