.NET: [Bug] : arguments null to Error message is: 'NoneType' object has no attribute items

[junkai-li]

Description

当AI调用 自定义的WriteTextToDesktop函数 传入了arguments：null ,我的函数参数都是必填 导致报错直接报错
下面是我捕捉的json

Code Sample

{
            "role": "assistant",
            "content": "下面是一个完全由我原创设计的科技风格 HTML 可视化页面，基于你提供的内容，涵盖架构、工具注入、技能加载、绑定管理等核心模块。\n\n",
            "tool_calls": [
                {
                    "id": "call_ffee0b78ef0b44d197647dd8",
                    "type": "function",
                    "function": {
                        "name": "WriteTextToDesktop",
                        "arguments": "null"
                    }
                }
            ]
        },  {
            "type": "function",
            "function": {
                "description": "输出文件到系统桌面。 用于把各种文件输出到桌面",
                "name": "WriteTextToDesktop",
                "parameters": {
                    "type": "object",
                    "required": [
                        "fileName",
                        "content"
                    ],
                    "properties": {
                        "fileName": {
                            "description": "\u6587\u4EF6\u540D\u79F0\u5982\uFF08xx.html,xx.txt\uFF09\u652F\u6301\u5404\u79CD\u6587\u4EF6\u7C7B\u578B",
                            "type": "string"
                        },
                        "content": {
                            "description": "\u5185\u5BB9",
                            "type": "string"
                        },
                        "overwrite": {
                            "description": "\u6587\u4EF6\u662F\u5426\u4E0D\u5B58\u5728 \u9ED8\u8BA4\u662F",
                            "type": "boolean",
                            "default": true
                        }
                    },
                    "additionalProperties": false
                }
            }
        },

Error Messages / Stack Traces

{"message":"<400> InternalError.Algo.InvalidParameter: Error message is: 'NoneType' object has no attribute 'items'","type":"invalid_request_error","param":null,"code":"invalid_parameter_error"},"id":"chatcmpl-2d4c0c6a-dfad-9df6-bf7f-cd61a3766458","request_id":"2d4c0c6a-dfad-9df6-bf7f-cd61a3766458"}

Package Versions

1.10.0

.NET Version

9

Additional Context

No response

[github-actions]

👋 Hi @junkai-li — thanks for the report!

The error you captured — 'NoneType' object has no attribute 'items' wrapped in <400> InternalError.Algo.InvalidParameter — is an HTTP 400 response from your AI provider's server-side Python code, not from the agent-framework. The error format (InternalError.Algo) and the Python-style exception message indicate the provider's backend validation crashed when the model generated "arguments": "null". The agent-framework itself has proper null handling for tool call arguments (both .NET and Python). This appears to be a bug or limitation in the specific AI model provider you are using — worth reporting to that provider's support team.

If you still believe there is a framework issue here, please reply with the exact import/class or method you are using, the version, and a minimal snippet that shows the failure. 🙏

[junkai-li]

别人使用mcp就不会出现这个问题 我使用的函数就有这个问题

[junkai-li]

tool 返回 Error: Function failed.