MCP Is More Useful as Context Distribution Than as RPC

Most discussions around MCP focus on tool calling. That is natural. When people first see MCP, the obvious use case is simple: Let the AI call external tools. A model can read a GitHub issue. A model can query a database. A model can update a file. A model can call an API. In that sense, MCP looks like an RPC layer for AI agents. That is useful. But I think it may not be the most important use of MCP. The more interesting use is this: MCP can distribute context, rules, skills, and operating contracts to AI clients. In other words, MCP is not only a way for AI to call tools during work. It can also be a way to define the working environment before the work starts. The problem with RAG RAG is usually used to answer this question: What information might be relevant to this request? The system searches documents, retrieves chunks, and gives them to the model. This works well for many cases. But it has structural limits. RAG retrieves likely relevant information. It does not necessarily define how the work should be done. For team-level AI work, this is a problem. A team does not only need information. A team also needs shared rules. For example: What is the authoritative source? What should be treated as unknown? When should the AI stop? When is human confirmation required? What is the closure condition? Which workflow should be used? Which domain skill applies? What evidence must be recorded? RAG can retrieve documents that describe these rules. But retrieval is not the same as governance. A retrieved chunk is just context. It is not necessarily an operating contract. The problem with local prompts Many teams try to solve this with prompts. They write instructions like: Follow our coding rules. Use this design document. Ask questions when unclear. Do not make risky changes. This helps, but it does not scale well. Each developer may have a different local prompt. Each AI client may load a different file. Each repository may contain a slightly different version of the ru