Worked on the harness/mcp-server repository to deliver new tools for delegate management and discovery, focusing on backend development using Go and API design. Built the list_delegates tool, enabling users to enumerate delegates with advanced filtering by status and type, and implemented a delegate lookup tool for quick retrieval by token. Refactored existing tooling to adopt a core_ prefix, updating related data transfer objects for consistency across the codebase. Enhanced reliability by adding end-to-end tests for the new features and updated documentation to streamline onboarding and usage. The work emphasized maintainability, operational efficiency, and clear, standardized tooling practices.