I Asked GitHub Copilot to Plan My Next Sprint: It Failed Spectacularly

Tried using GitHub Copilot in Visual Studio 2026 to generate a full Agile sprint plan for rewriting a legacy application. Results: Codex Mini: Produced a vague, waterfall-style plan → clear misunderstanding of Agile. Full Codex: Better terminology (Definition of Done, backlog, etc.) but still mostly fluff and unrealistic timelines. The plans focused on mechanical code conversion, missing the actual domain logic rewrite. Effort estimates were not realistic, especially without historical sprint ve