Sub Routine results

Quick question for the pros :

If I do :

sub my_routine {
        my $t = shift;
        return "You said $t";
}

$vars = {
  my_routine => \&my_routine
};

... then in the template ...

<P>
[% my_routine("my_arg here") %]
</P>

Will that simply print the return value of my_routine, in this case :
<P>
You said my_arg here
</P>

Or do I need to do a print statement or ???

Thanks

Dan