fix: description incorrectly passed as version to MCP server

[yousoumar]

Describe your changes

Fixed incorrect parameter passing to the MCP Server constructor. The Server constructor was being called with positional arguments, causing description to be passed as version:

# Before (incorrect)
Server(self.name, self.description)

# After (correct)
Server(self.name, version=self.version, instructions=self.description)

Fixes #293

Checklist before requesting a review

• Added relevant tests
• Run ruff & mypy
• All tests pass