Worked on enhancing observability and API ergonomics in the modelcontextprotocol/go-sdk by introducing a flexible client logging mechanism. Developed a Logger option within ClientOptions, allowing configurable logging and deprecating the legacy logger to unify the logging API. Focused on backend development using Go, the work included implementing comprehensive unit tests to validate the new logging behavior and ensure regression safety. Addressed issue #708 by streamlining the logging workflow and maintaining backward compatibility through careful test coverage. This update enables safer production debugging and provides developers with improved control over logging, contributing to a more robust and maintainable Go SDK.