I built a MCP server that solves this actually. It works like a tool calling proxy that calls child servers but instead of serving them up as direct tool calls, it exposes them as typescript defintions, asks your LLM to write code to invoke them all together, and then executes that typescript in a restricted VM to do tool calling indirectly. If you have tools that pass data between each other or need some kind of parsing or manipulation of output, like the tool call returns json, it's trivial to transform it. https://github.com/zbowling/mcpcodeserver