"Form Field: Set Validation Error" Description is not correct

Problem/Motivation

The Description for "Field name" under action "Form Field: Set Validation Error" is

The input name of the form field. This is mostly found in the "name" attribute of an form element. This property supports tokens. Leave empty to set a global error on the form.

However, when I leave it empty, the error appear:

action "Form field: set validation error" (): Field name field is required