Two agents passing strings to each other is not a multi-agent system — it's a pipeline, and the distinction matters

In the previous two posts I built a minimal Claude agent (Module 1) and then gave it multiple tools (Module 2). This is Module 3 — adding a second agent that critiques the first one's work and loops until approval. The system works. The output is better than single-agent. But building it changed what I think the word "multi-agent" actually buys you, and I want to be specific about where the real architectural line sits.

The setup

Two Python functions, each making a single Anthropic API call with a different system prompt:

pythondef run_designer(game_idea: str, criticism: str = None) -> str:

if criticism: