I am exploring the mcp server-memory. using n8n

** This is the MCP Client Github:

** This is the servers-memory Github

Image: This is the add_observation node tool

Image: This is the example workflow

Error encountered:

Failed to execute operation: Failed to execute tool 'add_observations': MCP error -32603: Cannot read properties of undefined (reading 'includes')

I had tried to use as a node instead of a tool, like in the picture below: Image but it still appear the same error. I am wondering is the json wrote wrongly? but shouldn't.