Is MCP just the same thing as tool use in Claude?

This is a common misconception. MCP servers and tool use are complementary but different concepts. MCP servers provide tool schemas and functions that are already defined for you, while tool use is about how Claude actually calls those tools at runtime. The key difference is who does the work. With plain tool use, you author the tools. With MCP, someone else has already implemented the tools for you, and Claude just calls them through the same tool use mechanism. So MCP sits one level above tool use: it is a way to source tools, not a replacement for the calling mechanism itself.