ToolResultBlock

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/ToolResultBlock",
  "title": "ToolResultBlock",
  "additionalProperties": false,
  "type": "object",
  "required": [
    "type",
    "tool_use_id",
    "content"
  ],
  "description": "A tool result content block supplied by the user in response to a tool call.",
  "properties": {
    "type": {
      "const": "tool_result",
      "type": "string",
      "description": "The block type, always `tool_result`."
    },
    "tool_use_id": {
      "type": "string",
      "description": "The `id` of the `tool_use` block this result responds to."
    },
    "content": {
      "anyOf": [
        {
          "type": "string"
        },
        {
          "type": "array",
          "items": {
            "$ref": "#/components/schemas/TextBlock"
          }
        }
      ],
      "description": "The tool's output. Pass a string for simple results or an array of text blocks for structured output."
    },
    "is_error": {
      "type": "boolean",
      "default": false,
      "description": "Set to `true` if the tool call raised an error."
    }
  }
}