How can we prevent a supervisor agent from routing on greeting-only messages?

Summary:

We’re building a supervisor agent that manages six worker agents. When users interact with the system using simple greetings like “Hi,” “Hey,” or “Good morning,” the supervisor still routes the request to one of the worker agents—even though we added prompt-level restrictions to prevent this. Any ideas on how to effectively block routing for greeting-only inputs?

Content (please ensure you mask any confidential information):

Version (include the version you are using, if applicable):

25D

Code Snippet (add any code snippets that support your topic, if applicable):