Worked on the strands-agents/sdk-python repository to enhance the reliability of tool invocation by addressing a critical timing issue in the retrieval of tool specifications. Using Python and backend development skills, implemented a fix that ensures tool specs are fetched after the before_model_invocation callback, allowing any changes made during the callback to be accurately reflected. This adjustment reduced the risk of using outdated or incorrect tool specifications, improving the determinism and production readiness of the SDK. The work demonstrated a strong understanding of lifecycle events and debugging, focusing on code quality and the robustness of backend processes within the Python ecosystem.