I spent the long weekend pushing Logic Apps MCP server capabilities further than I had before — and hit two bugs worth documenting. Both are filed. If you're building in this space, save yourself the debugging time. Context If you've been following along, the MCP server and BODMAS Agent are covered in the previous posts. This post is just about what broke when I wired them together. Bug 1 — Intermittent duplicate key error at tool registration What happens The Agent Loop fails with a BadRequest before making a single MCP call: HTTP request failed: 'An item with the same key has already been added. Key: {tool_name}'. Enter fullscreen mode Exit fullscreen mode The key referenced in the error — BasicArithmeticMCP , ExtendedArithmeticMCP , whatever you name it — appears exactly once in the workflow definition. There is no actual duplicate in the JSON. What makes it particularly frustrating to diagnose It is intermittent. Some runs fail, others succeed with identical configuration and identical input.…