There is some confusion in a WebmasterWorld thread, where advertisers are asking where the Tools tab in the AdWords management console went.
If your tool tab is missing, it is likely because you have been included into the new beta "opportunities" tab. This does not mean you don't have access to those tools, they are just moved.
To find the tools, click on "opportunities" and on the left side bar, you will see a box for "tools." The tools can be found in that box. Here is a picture:
Forum discussion at WebmasterWorld.