Developed a telemetry enhancement for the OfficeDev/teams-toolkit repository, introducing a new property to track the origin of CLI invocations. The solution leveraged TypeScript and focused on privacy by implementing an allowlist-based normalization mechanism, ensuring that telemetry data remained low-cardinality and free of personally identifiable information. The approach derived the caller-source property from the ATK_CALLER environment variable, collapsing unknown values to a generic category to maintain data hygiene. Comprehensive unit tests were written to validate both the normalization and filtering logic, demonstrating a methodical approach to reliability and observability in CLI development and telemetry data collection workflows.