graph TD
subgraph MCP
direction LR
MCP_HostClient["Host/Client (AI App)"] -- "1 Connect & Discover" --> MCP_Server["MCP Server"]
MCP_Server -- "2 Exposes Primitives" --> MCP_HostClient
MCP_HostClient -- "3 Invokes Tool/Resource" --> MCP_Server
MCP_Server -- "4 Executes & Returns Result" --> MCP_HostClient
MCP_Server -- "Manages" --> MCP_Primitives["Primitives: Tool, Resource, Prompt"]
end