fvtt-pegasus-rpg/templates/partial-item-description.html

<div class="tab description" data-group="primary" data-tab="description">
  <div>
    <label class="generic-label">Description</label>
    <div class="medium-editor item-text-long-line">
    {{editor content=data.description target="data.description" button=true owner=owner editable=editable}}
    </div>
  </div>
</div>