AI 中文总结
本文从多智能体系统工程角度，以涉及基于大语言模型智能体的协调场景，比较MCP和A2A协议。针对多项要求评估同一软件工程任务的两种多智能体实现，发现MCP协调复杂度低，A2A支持更丰富，但都有特点，为智能体间协调协议设计提供了经验和权衡要点。
AI 中文摘要
近期行业实践中，由异构、工具和大语言模型介导的智能体组件组成的智能体系统迅速涌现，引发了智能体间协调和协议设计的实际问题。本文从多智能体系统工程角度，以涉及基于大语言模型的智能体的协调场景，对模型上下文协议（MCP）和智能体到智能体（A2A）协议进行了基于实现的比较。针对从先前文献及与行业伙伴讨论得出的一组要求，评估了同一软件工程任务的基于MCP和基于A2A的多智能体实现，包括智能体可发现性、多部分消息传递等。结果表明，MCP能通过更轻量级实现模型在受限的基于大语言模型的系统中支持智能体间协调，协调复杂度较低，但对话状态管理等需在应用层显式实现。相比之下，A2A通过任务和生命周期管理的协议级抽象为有状态、多轮协调提供了更丰富的原生支持，但实现和协调复杂度更高。鉴于评估的协调模式范围较窄，这些发现是基于实证经验报告的设计观察，而非对更广泛的多智能体系统类别的协议适用性或优越性的一般主张，突出了权衡以及协议抽象如何塑造当代智能体系统中协调责任的分布。
英文摘要
Recent industry practice has seen the rapid emergence of agentic systems composed of heterogeneous, tool- and LLM-mediated agent components, raising practical questions about inter-agent coordination and protocol design. This paper presents an implementation-grounded comparison of the Model Context Protocol (MCP) and the Agent2Agent (A2A) protocol, from a multi-agent systems engineering perspective, using an inter-agent coordination scenario involving LLM-based agents. We evaluate an MCP-based and an A2A-based multi-agent implementation of the same software engineering task against a set of requirements derived from prior literature and discussions with industry partners, including agent discoverability, multi-part messaging, multi-turn conversations, asynchronous communication, observability, interoperability, and access control. The results evidence that MCP can support inter-agent coordination in constrained LLM-based systems through a comparatively lightweight implementation model with lower coordination complexity, although coordination concerns such as conversational state management and task lifecycle handling must be implemented explicitly at the application layer. In contrast, A2A provides richer native support for stateful, multi-turn coordination through protocol-level abstractions for tasks and lifecycle management, but this comes with substantially greater implementation and coordination complexity. Given the narrow scope of the evaluated coordination pattern, these findings are presented as design observations from an empirical experience report rather than general claims of protocol suitability or superiority across broader classes of MAS, highlighting trade-offs and how protocol abstractions shape the distribution of coordination responsibilities in contemporary agentic systems.
Comments18 pages
