Pull: Tool object doesn't instantiate

[Dave Hollar]

I'm trying out the Pull service with a simple tool class, inheriting from 
ApplicationTool.  I've put the entry in the config file for the tool but when a screen 
tries to access it, a message is logged saying "Could not instantiate tool 
com.bizpiranha.bia.tools.MyTool to add to the context."

My build was successful and it seems to be in the classpath.  What am I overlooking?

thanks in advance-
Dave