I'm not too sure what "MCP-based methodology" is, but Jan-nano-128k is a small model specifically designed to be able to answer in-depth questions accurately via tool-use (researching in a provided document or searching the web).

It outperforms those other models, which are not using tools, thanks to the tool use and specificity.

Because it is only 4B parameters, it is naturally terrible at other things I believe-it's not designed for them and doesn't have enough parameters.

In hindsight, "MCP-based methodology" likely refers to its tool-use.