MSBuild: Part 2

I am going through this tutorial about automating the build with MSBuild. The first task with the Build Script seems fairly basic – adding a command to delete the files in the /bin directory. The interesting thing I found was that the valid code does not have intellisense support:

But when I run it:

Sure enough, the files are gone.

I guess BinFiles was added after the created the code comments? Baffling.