Workflow mandatory tag Follow

Hi,
I have created a workflow to force users to select a tag when they are creating a new issue :

rule tag mandatory 
when issue.isRepordte(){
   tags.required("select one tag");
}

It is working well: when I submit my issue, it is blocked if there is no tag.

But a command prompt is shown, with a command line starting with "tags" ..
Is there a way to not show this prompt, only the error message ?

thx
Fabien