Worked on the deer-flow repository to enhance the Write File Tool by improving parameter documentation and making the append argument more discoverable within the model-facing schema. Focused on backend development using Python, the work included adding regression tests to ensure all public tool parameters are properly documented, which improved both usability and supportability. Maintained existing runtime behavior while aligning backend tests and documentation with the updated tool features. Addressed code quality by fixing lint errors and collaborating closely with other contributors to ensure adherence to project standards. The improvements reduced support risk and provided clearer guidance for users interacting with the tool.