Governing MCP tool calls in .NET with the Agent Governance Toolkit

The Agent Governance Toolkit (AGT) provides a .NET governance layer for MCP tool calls in AI agent systems. It includes McpSecurityScanner for detecting malicious tool definitions (e.g., prompt injection, typosquatting), McpResponseSanitizer for cleaning tool outputs, McpGateway for policy-based access control, and GovernanceKernel for wiring everything together with YAML policies, audit events, and OpenTelemetry. The toolkit maps to the OWASP MCP Top 10 risks and requires no external services. Install via the Microsoft.AgentGovernance NuGet package targeting .NET 8.0+.