Why do workflow tools need to return two identical results? One is JSON, and the other is TEXT

[swingchen01]

Self Checks

• I have searched for existing issues search for existing issues, including closed ones.
• I confirm that I am using English to submit this report (我已阅读并同意 Language Policy).
• [FOR CHINESE USERS] 请务必使用英文提交 Issue，否则会被关闭。谢谢！:）
• Please do not modify this template :) and fill in all the required fields.

Content

Why does the workflow tool 'workflow_tool.py' return a TEXT text result with the same result as JSON in addition to the JSON result during its execution? Are there any special scenarios to consider?
The above program logic will result in the tool results returned in the [ToolEngine. _convert_tool_response_to_str()] method, and two identical results will be obtained. This will cause the FunctionCallAgentRunner to provide the duplicate tool results to the LLM's API, which will take up twice the number of tokens.