"If your task can be expressed as a workflow, build a workflow". 100% true but the thing all these 'agent pattern' or 'workflow' diagrams miss is that real tasks require back-and-forth with a user, not just a Rube Goldberg machine that gets triggered in response to a _single user message_.
What you need is not 'tool use' but something like 'process use'. This is what we did at Rasa, giving you a declarative way to define multi-step processes. An LLM lets you have a fluent conversation, but the execution of the task is pre-defined and deterministic: https://rasa.com/docs/learn/concepts/calm/
The fact that every framework starts with a `while` loop around an LLM and then duct-tapes on some "guardrails" betrays a lack of imagination.