How do I pull in a group of term descriptions instead of their names?
One quick way to solve it with code would be to add a custom field formatter:

function MYMODULE_field_formatter_info() {
  return [
    'taxonomy_term_csv_descriptions' =&gt; [
      'label' =&gt; t('Taxonomy term CSV descriptions'),
      'field types' =&gt; ['taxonomy_term_reference'],
    ],
  ];
}

function MYMODULE_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $element = [];

  if ($display['type'] == 'taxonomy_term_csv_descriptions') {
    $descriptions = [];

    foreach ($items as $item) {
      $descriptions[] = check_markup($item['taxonomy_term']-&gt;description, $item['taxonomy_term']-&gt;format);
    }

    $element[0] = ['#markup' =&gt; implode(', ', $descriptions)];
  }

  return $element;
}


That will give you a new formatter to use for taxonomy term reference fields in Views or the Manage Display pages for content types.

If you go with this solution you can remove the relationship to the Taxonomy Term from your View.