Plan-and-Execute & ReWOO

Two planning-oriented alternatives to ReAct's step-by-step loop. Plan-and-Execute
generates a full plan upfront and then executes each step; it is efficient and
inspectable for predictable tasks but adapts poorly when an early step produces an
unexpected result. ReWOO (Reasoning Without Observation) is the most
token-efficient pattern for multi-step work: it plans once with placeholders,
dispatches the tool calls in parallel, and synthesises at the end — often in only a
couple of model calls. Students learn to weigh adaptability against cost and
inspectability.