Agent Optimizer, Agent Plugins 1.0 & Sonnet 4.6 Sunset
Agent Plugins 1.0 GA unifies MCP and skills into one cross-platform open standard
“One package, multiple clients, one thing to version.”
Microsoft released three notable developer updates: Agent Optimizer in Microsoft Foundry showed benchmark improvements for every tested agent without model changes; Agent Plugins 1.0 reached GA across VS Code, Copilot CLI, and the Copilot SDK as an open standard backed by AWS, Anthropic, Microsoft, OpenAI, Vercel, and Google. Additionally, Claude Sonnet 4.6 is being sunset from most GitHub Copilot experiences on September 1st, giving enterprise teams a two-week window to update hardcoded model references.