error: unknown toolset type: background_agents

[pranjal-rajput]

Describe the bug

When launching a basic yaml with background_agents toolset, its reporting warning:
time=2026-03-17T13:26:31.242+11:00 level=WARN msg="Toolset configuration failed; skipping" type=background_agents ref="" command="" error="unknown toolset type: background_agents"

Docker version 29.2.1, build a5c7197

Please include the version of the software that you are using.
(paste the output of the version command)

How To Reproduce

Detailed steps to reproduce the behavior:

1. create a yaml with 2 agents
2. one agent to have toolsets - type:background_agents
3. docker agent run .yaml
4. See warning popup on the bottom right corner of the screen

Expectation

this is a built-in toolset so , warning/error should not be there

Screenshots

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Especially useful if the problem is visual (rendering issues etc.) or you're not totally sure how to explain the problem and need to show it to us

OS and Terminal type

MacOS Tahoe 26.2, iTerm 3.6.8

Additional context

[pranjal-rajput]