<ul data-eligibleForWebStory="true">MCP 2025-06-18 Spec Update enhances security with OAuth 2.0 Resource Server classification.Structured JSON tool output supported, along with elicitation for user input mid-session.New Security Considerations, PKCE protection, and token audience validation for MCP servers.Added Security Best Practices with concrete countermeasures and structured output schema support.Resource links in tool results, protocol version enforcement, and JSON-RPC batching removed.