I don't think they're comparable. RTK just modifies the output of CLI tools to reduce the number of tokens, a Roslyn MCP gives the agent a fundamentally superior way of interacting with a C# codebase.

My main issue with rtk is that rtk randomly messes modification and agent start polling same tool continuously.

Yes. and i find model makes less errors and reasoning the codebase well, especially when you do a large refactor.