Prompts have been useful for jumpstarting developer-agent collaboration but fall short at scale due to their lack of persistence, reproducibility, and governance, leading to issues like "prompt fatigue" and inconsistent outputs. Collaborative spec-driven development offers a solution by replacing ad-hoc prompts with structured workflows, creating a shared space for teams to align on execution and maintain an audit trail of decisions. This approach transforms fragile prompts into repeatable, auditable automation, allowing enterprises to use AI workflows for tasks such as code migrations and incident response. Runbooks serve as a practical implementation, turning AI-assisted coding from a single-player activity into a collaborative one by embedding context, securing execution, and providing preconfigured environments. Spec-driven workflows are more predictable, reproducible, and collaborative, making them superior for scalable, secure, and reproducible collaboration, especially in enterprise environments, while prompts are best suited for quick, exploratory tasks.