AI Agent Node error in prompting

Questions
1

I’m creating a multi-agent system in n8n.

Basically, I have an orchestrator agent and 5 other AI agents (tools).
In the AI ​​Agent tools, I set the prompt to “Defined automatically by the model”.
The problem is that sometimes the orchestrated agent returns:
{{ $fromAI(‘Prompt__User_Message_’, , 'string') }} and other times {{ $fromAI('Prompt__User_Message', , ‘string’) }}

Then the node agent (tool) ends up receiving an empty prompt.

What could be happening?

2

Hi @Luis_Miguel
i have personally felt that, and what i have done is that instead of letting the AI agent define the prompt what i do is that i curate a very open ended PROMPT and then manually enter there, so that i know what i want that agent to perform so that is why manually defining it is way better, and the defined by model is a bit inconsistent i would say. But it mostly works in fields where it does not need to think much.