Outlook add attachment to message

{
  "type": "object",
  "properties": {
    "messageId": {
      "type": "string",
      "description": "Draft message ID"
    },
    "@odata.type": {
      "type": "string",
      "description": "Microsoft Graph attachment type"
    },
    "name": {
      "type": "string",
      "description": "Attachment filename"
    },
    "contentBytes": {
      "type": "string",
      "description": "Base64-encoded attachment content"
    },
    "contentType": {
      "type": "string",
      "description": "Attachment MIME type"
    },
    "isInline": {
      "type": "boolean",
      "description": "Whether the attachment is inline"
    }
  },
  "required": [
    "messageId",
    "name",
    "contentBytes"
  ],
  "description": "Input schema for the outlook__add_attachment_to_message tool."
}