In the past, the relationship between AI models and the external world resembled that of isolated "intelligent islands." Each model possessed its own plugin system and interface standards, requiring extensive repetitive development for any cross-model or cross-tool calls. Anthropic's MCP protocol, open-sourced in November 2024, attempts to break this closed system. By providing a unified interface for large language models from different vendors and with different architectures, it allows all applications to become part of a larger intelligent system. MCP standardizes the interaction between models and tools, employing a client-server architecture. The MCP server exposes a set of tool interfaces and provides a unified description, allowing MCP clients to query and invoke available tools at runtime. Its advantage lies in significantly simplifying cross-model and cross-tool integration costs; theoretically, only a single adaptation to the MCP protocol is needed to use any compatible tool. MCP enhances scalability and dynamism: when a new tool is integrated into the system, model applications can discover and use it in real time without modifying existing code. This process not only reduces tool integration development but also minimizes instability in cross-ecosystem (cross-model, cross-tool) calls. MCP's biggest advantage is its significant reduction in the workload of system connections. Previously, if M services needed to connect to N data sources, a total of M x N interface developments were required. However, with the MCP protocol, only M+N connections are needed to build a complete and stable service. This is why the MCP ecosystem has gained acceptance and has been rapidly adopted by numerous services. The emergence of MCP not only simplifies the model integration process but, more importantly, drives the shift from a "plugin ecosystem" to a "protocol ecosystem." The tool layer is becoming a shareable and interoperable protocol layer, laying the foundation for collaborative work between different models. As more models and tools adopt the MCP protocol, AI is gradually moving from individual intelligence to networked intelligence.