I have created a very basic MCP server that provides one tool - a calculator that performs addition/subtraction operations on two numerical values.
I have created a custom connector for that MCP server based on the documentation (https://learn.microsoft.com/en-us/microsoft-copilot-studio/agent-extend-action-mcp)
As a result my custom connector has two actions
- acquire a connection to MCP server (via /sse path)
- handling of messages to MCP server (via /messages path)
However, I am facing some issues when trying to use the custom connector based actions in Copilot Studio agent:
- when creating an action in Copilot Studio, neither of the actions have any input parameters (when I use the action from the custom connector in Power Automate, input parameters are showing up correctly)
- using an action to acquire a connection to MCP server ends up in agent becoming unresponsive (this is probably due to the fact that /sse endpoint is jsonrpc and does not work in immediate request/response fashion)
- when using an action to send a message to MCP server, I get no response from the agent
Am I missing something? I believe the problem is most likely with my custom connector definition, but I've been trying many things and nothing worked. I can provide the connector definition if needed.