Conversation so far:
Who played Yoda?
CANNOTANSWER.
Why was Yoda important in this film?
In Revenge of the Sith, Yoda leads the Jedi Council in pursuing the mysterious Sith Lord Darth Sidious.

Question: was he successful in this?
Self-contained rewrite: In Star Wars Episode III: Revenge of the Sith, was Yoda successful leading the Jedi Council in pursuing the mysterious Sith Lord Darth Sidious?