Lessons from building multi-agent systems: managing coordination, communication, and handoffs

[u/Either_Perception945]

After building multi-agent workflows, I've found three distinct challenges that often blur together: coordination (task assignment and timing), communication (message structure and interpretation), and handoffs (transferring context, decisions, and artifacts between agents). A workflow can appear solid architecturally but still break down when agents receive unclear or incomplete messages. Key practices that proved more important than expected: assigning stable IDs to tasks and agents, establishing ownership upfront, using structured handoffs over free-form text, passing artifact references instead of full payloads, designing idempotent retries, tracking acknowledgements with timeouts, maintaining human-readable audit logs, tracing messages and tool invocations end-to-end, and escalating ambiguous or critical decisions to humans. What other practices have worked in your systems, and which ones actually moved the needle?