As the title describes, Is there a tool that tells us if competitor is running Adwords?

There are a bunch of sites that will tell you.

Keywordspy is one. You simply type in the name of the site and you will be able to see all of their keywords and ads.

To download the entire list, you would need to pay a monthly fee, but to just see if they are doing anything is free.

There's this tool called Google as well.