Function createToolResultMessage

source code/utils/messages.ts:4290–4325

(
  tool: Tool<AnyObject, Output>,
  toolUseResult: Output,
)

}

function createToolResultMessage<Output>(
  tool: Tool<AnyObject, Output>,
  toolUseResult: Output,
): UserMessage {
  try {
    const result = tool.mapToolResultToToolResultBlockParam(toolUseResult, '1')

    // If the result contains image content blocks, preserve them as is
    if (
      Array.isArray(result.content) &&
      result.content.some(block => block.type === 'image')
    ) {
      return createUserMessage({
        content: result.content as ContentBlockParam[],
        isMeta: true,
      })
    }

    // For string content, use raw string — jsonStringify would escape \n→\\n,
    // wasting ~1 token per newline (a 2000-line @-file = ~1000 wasted tokens).
    // Keep jsonStringify for array/object content where structure matters.
    const contentStr =
      typeof result.content === 'string'
        ? result.content
        : jsonStringify(result.content)
    return createUserMessage({
      content: `Result of calling the ${tool.name} tool:\n${contentStr}`,
      isMeta: true,
    })
  } catch {
    return createUserMessage({
      content: `Result of calling the ${tool.name} tool: Error`,
      isMeta: true,
    })
  }
}

function createToolUseMessage(
  toolName: string,