Question Regarding send/post sunshine Message API Endpoint

I had a question regarding the send/post message API endpoint (link of doc: https://developer.zendesk.com/api-reference/conversations/#tag/Messages/operation/PostMessage).
api endpoint: https://{subdomain}.zendesk.com/sc/v2/apps/{appId}/conversations/{conversationId}/messages
with body for sending attachments:
{

  "author": {

    "type": "business"

  },

  "content": {

    "type": "image",

   “mediaUrl”: “xyz”

    "text": "very big text"

  }

}

If the content.type is set to "image", is there any limitation on the content.text character length? Specifically, if the text field contains a long string, is there a maximum character limit that could potentially cause an error?