Unknown in the article Autonomous agents - Technique 3: Provide tools for steps your agent can’t easily handle (like Agent Flows) (published February 8, 2026):

They need to call out to tools which are pre-defined and wrap up the complex details of taking actions on specific systems, integrating data, or performing precise steps in a process. Every agent framework has a ‘tools’ concept, and for Microsoft agents built with Copilot Studio, this is agent flows

Keeping post for reference. Express mode seems to be new.