The phrase "smart idea" means a clever or intelligent suggestion or thought. It refers to an idea that is well-thought-out and likely to be effective or beneficial. Full definition
Yeah... this is a pretty smart idea for them to do. (n4g.com)
Improving the app for tablet owners was a very smart idea as well. (laptopthoughts.com)
That's why we put together this list of four really smart ideas of what to spend your refund money on, as well as three really bad ideas. (policygenius.com)