Forum Discussion
Agent with Fabric data agent tool times out at 100s even in background mode
Your test shows the Fabric data-agent call is still failing at the MCP client’s 100-second HTTP timeout. Polling the background response cannot extend a tool request that the platform has cancelled. Microsoft’s Foundry guidance says long-running MCP work requires a background-mode-capable model and an MCP server that supports tasks; it also documents a 100-second limit for non-streaming MCP calls. Confirm the model, API version, agent definition, and Fabric connection are using the current task-capable path. Capture the response ID, tool-call output, region, server capability response, and timeout timing for a Microsoft support request. I cannot identify a setting that forces Foundry to negotiate the older task capability format you observed. Until that path is supported, reduce the Fabric operation so each call returns within 100 seconds, split the query into stages, or run the longer task directly against the MCP server and pass its completed result back to the agen
According to the current Microsoft Foundry documentation, Fabric Data Agent MCP endpoints are specifically documented as supporting long-running operations through Background mode. The docs also state that Background mode allows MCP tool calls to exceed the standard 100-second non-streaming timeout.
In the screenshot below you can see that I am using:
- a background-capable model (gpt-5.6-luna)
- the Fabric IQ connection to the Fabric Data Agent
- Background mode enabled
- the run actually starts as a background task
However, the Fabric Data Agent tool call still fails with:
HttpClient.Timeout of 100 seconds elapsing
So the background response itself is working, but the internal Fabric Data Agent MCP call is still being cancelled at the synchronous 100-second limit.
This is the part I am trying to understand: is this currently a limitation/bug in the Foundry ↔ Fabric Data Agent integration, or is there an additional setting required for the Fabric IQ tool call to actually run as a long-running MCP task?
Microsoft’s documentation says that, among Fabric IQ item types, the Data Agent MCP endpoint is the one that supports long-running operations through Background mode, and that in the portal the expected flow is to enable Background mode, add the Data Agent through Fabric IQ, and send the query.
Doc capture:
https://learn.microsoft.com/en-us/azure/foundry/agents/how-to/tools/model-context-protocol?view=foundry&pivots=python#long-running-operations-preview
Failed test capture:
