Implement Call.MCP task

[mrsimonemms]

Is your feature request related to a problem? Please describe

Missing Serverless Workflow spec

Describe the behaviour you'd like

Implement Call.MCP

Describe alternatives you've considered

Additional context

[Rapteon]

Is this issue still open for work? If yes, I'd love to work on it.

[mrsimonemms]

@Rapteon Yes, go for it. If you want to discuss design etc, please chat in Slack