Form toolkit -- can't get tooltip to work with component as described in doc topic or in tests

Development
3

When I do something like that, the tooltip is just added to the field name.

@tooltip just wants a string. Once I realized that, I just made a function that returns a string like

  @action
  tooltipText(field) {
    return i18n("pfaffmanager.help." + field + "_tooltip");
  }
...
               <form.Field
              @name="install_type"
              @format="large"
              @translatedLabel="bananas are delicious"
              @validation="required"
              @tooltip={{this.tooltipText "install_type"}}
              @class="install-field"
              @title="Install Type"
              {{! @description="description." }}
              as |field|
            >
              <field.Select
                {{on "focus" (fn this.fieldClicked "install_type")}}
                as |select|
              >

This seems like another case where the documentation is just wrong.