Provided Variables Replacement pattern not working

I'm working on a module that provides a variable. The variable shows up correctly in data selection mode but not in Direct Input Mode. If I put in [variable-value], it shows up as [variable-value], instead of the actual value. Is there something I need to do besides simply providing the variable name, type, and value?

<?php

  $actions['rules_action_create_variable'] = $defaults + array(
    'label' => t('Create Variable'),            
    'provides' => array(
      'created_variable' => array(
        'type' => 'text', 
        'label' => t('Created variable'),  
      ),
    ),

  );
?>