I thought MCP interfaces with high amounts of tools perform much worse than MCP interfaces with fewer tools, this doesn't seem like a great design.

This also seems to just be vibecoded garbage.

Haven't looked at the app itself but the MCP tool problem is mainly solved now using lazy loading, it's far from perfect but the immediate context window overload problem is gone (in clients that support it anyway).

Now just onto the fact that most MCP tools are just transforming API calls and their functionality and return data structures suck for LLM's....

True. Though vibecoded skill-based tools would perform much more efficiently than this.