[galaxy-dev] optional="false" not working?

Hello, I have the following wrapper: <tool id="foo" name="foo" version="0.99.0"> <description>foo</description> <command interpreter="python"> tool.py $outputFileName </command> <inputs> <param name="tp" type="text" label="label" help="help" optional="false"/> </inputs> <outputs> <data format="csv" name="outputFileName"/> </outputs> </tool> I expect that when I click "Execute" I will be told that "tp" must have a value. However, that doesn't happen, it just goes ahead and executes the script. How do I get Galaxy to require that a text param have a value? Thanks, Dan