[p4] Tag and Label via cmd line with description

[peter mcgrath]

Hi

I have an ANT script where I'm trying to create a label and I'm using that
label to Tag a Project, I want to have the description\comment for the label
go in with the tag, which presently I have not found any info on. When I
execute the command  <arg line="p4 label -i ${label} //depot/test/..."/> I
get the error:
[exec] Usage: label [ -d -f -i -o -t template ] labelname
     [exec] Missing/wrong number of arguments.
     [exec] Result: 1

So if anyone knows how I can create a label without the above error would be
great, but that aside I need to know how to add the description to a TAG as
the code is tagged but there is no description only who created the tag. Any
and all help and hints are welcome.

<target name="test-label">

   <echo>Label: P4: labelling tree //depot/test/... ${label}</echo>
  <exec executable="cmd">
       <arg value="/c"/>
        <arg line="p4 label -i ${label} //depot/test/..."/>
     </exec>
  <exec executable="cmd">
       <arg value="/c"/>
        <arg line="p4 tag -l ${label} //depot/test/..."/>
     </exec>
 </target>