core/homeassistant/components/tts/services.yaml

say:
  description: Say some things on a media player.

  fields:
    entity_id:
      description: Name(s) of media player entities.
      example: 'media_player.floor'

    message:
      description: Text to speak on devices.
      example: 'My name is hanna'

    cache:
      description: Control file cache of this message.
      example: 'true'

clear_cache:
  description: Remove cache files and RAM cache.