What changed
Microsoft announced Agent Harness, hosted execution, CodeAct-style tool use and related framework updates for building and operating agents across its development stack.
Why it matters
Separating the harness from the model makes execution policy, state, tools and hosting explicit components that teams can version and evaluate.
What to do
Port one small workflow to the new harness, freeze model and tools and compare trace completeness, recovery and policy enforcement with the current framework.
Caveat
Several Build features were previews, the stack is Microsoft-centered and framework adoption does not by itself improve task reliability.