Worked on the pydantic/pydantic-ai repository to deliver OpenAI Strict Mode for Tool Calls, introducing a strict parameter to tool definitions and model requests that enforces JSON schema compliance in OpenAI function calls. This feature was implemented using Python and focused on schema validation and API integration, aiming to improve the robustness and predictability of production systems by reducing schema-related errors. The work included updating documentation and tests to reflect the new strict mode behavior, ensuring comprehensive coverage and clarity for users. The contribution demonstrates a methodical approach to full stack development and large language model integration within the project.