Microsoft released the Agent Governance Toolkit in April 2026. MIT license, ~1,000 GitHub stars in the first two weeks, 13 packages covering trust scoring, policy enforcement, and protocol bridges. For governing agents inside a single organization, it's the most complete open-source option available.

The comparison gets interesting when an agent from a different organization shows up.

That's the structural gap this post covers: what AGT does exceptionally well, where the architecture stops by design, and what cross-org behavioral trust requires that a deployment-scoped toolkit cannot provide.

This isn't a competitive takedown. AGT is genuinely well-engineered. The gap isn't a flaw — it's a scope decision. Understanding it helps you deploy the right tool for the right problem.

What AGT Provides

AGT ships eight production-grade packages. The core capabilities:

Trust scoring.…