Handoff is Where the Agent Dies: 3 Patterns That Fix It

When deploying multi-agent systems, handoff failures often occur. Agent A completes its task and passes control to Agent B. However, Agent B lacks context of what A did, files it touched, or errors encountered. This loss of context is known as the Classic Handoff Disaster.

Pattern 1: Artifact Chaining helps prevent this issue. Instead of merely passing instructions, share evidence of what happened. Introduce a Handoff interface with required fields such as from (the source agent), to (the receiving agent), nextTask (the task to be handled by the receiver), and artifacts (a list containing the path, type, and summary of evidence). This allows the receiving agent to verify if research produced outputs and understand discovered edge cases.

Pattern 2: Contract Testing during handoff is another crucial pattern. Before transferring control, validate the received artifacts against a contract. Define a contract object specifying required artifacts, expected outputs, and quality thresholds. The contract verification checks if all required artifacts are present in the received handoff and ensures that the outputs meet quality thresholds. If any artifacts are missing or quality criteria are not met, an error is thrown.

Pattern 3: A Shared Memory Repository enables agents to maintain a shared knowledge base. Implement a SharedMemory class with methods to write, read, and query data. Agents can update the shared repository with relevant information such as research findings, constraints, and edge cases discovered during their tasks. Other agents can then query the shared memory to retrieve this information, ensuring continuity and context across handoffs.

By applying these three patterns—Artifact Chaining, Contract Testing, and Shared Memory Repository—agents can effectively pass context during handoffs, preventing wasted work, broken outputs, and user dissatisfaction.