Help with an action

I still can't get my head around building my own actions. What I'm trying to do is create an action that'll add the artist in brackets to the end of the title. So that the title looks like this:

The Three Stooges [ABC]

Could any one be kind enough to help me out? Thanks.

Action type: Format value
Field: TITLE
Format string: %title% '['%artist%']'

You are the man! This saves me a ton of time. Thank you!