core/homeassistant/components/tts/services.yaml

# Describes the format for available TTS services

say:
  name: Say a TTS message
  description: Say something using text-to-speech on a media player.
  fields:
    entity_id:
      name: Entity
      description: Name(s) of media player entities.
      example: "media_player.floor"
      required: true
      selector:
        entity:
          domain: media_player
    message:
      name: Message
      description: Text to speak on devices.
      example: "My name is hanna"
      required: true
      selector:
        text:
    cache:
      name: Cache
      description: Control file cache of this message.
      example: "true"
      default: false
      selector:
        boolean:
    language:
      name: Language
      description: Language to use for speech generation.
      example: "ru"
      selector:
        text:
    options:
      name: Options
      description:
        A dictionary containing platform-specific options. Optional depending on
        the platform.
      advanced: true
      example: platform specific
      selector:
        object:

clear_cache:
  name: Clear TTS cache
  description: Remove all text-to-speech cache files and RAM cache.