adk 调用 tool 在参数为空情况下报错

如图，非 stream 没测试，但是有参数的 tool 没有报错。只有不需要传参的工具有问题（tool 是个 mcp，应该没关系）

Start by reproducing the ADK call to an MCP tool that requires no parameters, comparing it with a parameterized tool. The issue notes that non-stream behavior has not been tested, so check both invocation modes if the relevant entry points can be located. Done means no-argument tool calls no longer produce the reported error.

Written by the indexing model from the issue text.