Microsoft has released an open-source runtime security toolkit designed to govern autonomous AI agents in enterprise environments. The Agent Governance Toolkit addresses all 10 OWASP agentic AI risks including goal hijacking, tool misuse, and identity abuse through sub-millisecond policy enforcement. The toolkit provides cryptographic identity management, zero-trust agent communication protocols, and compliance mapping to frameworks like the EU AI Act and HIPAA. Organizations can now deploy enterprise-grade AI agents with verifiable audit trails, trust scoring systems, and automated governance verification. This release represents a significant step toward making autonomous AI systems production-ready for critical business applications.