Worked on enhancing the Claude Agent SDK Python repository by introducing improved message context tracking for subagent interactions. Developed a feature that adds a parent_tool_use_id attribute to both UserMessage and AssistantMessage classes, enabling more precise traceability of message lineage across multi-tool orchestration scenarios. Updated the backend parsing logic in Python to ensure that the origin tool context is consistently propagated throughout the conversation flow. Incorporated unit testing to validate the new attribute and parsing behavior, focusing on reliability and robustness in message handling. The work emphasized backend development, data parsing, and thorough test coverage to improve observability within the SDK.