sequenceDiagram
    participant Client as Client/TCP
    participant Service as tool_service
    participant Codec as codec
    participant Exec as tool_exec
    participant Output as display_output

    Client->>Service: DISPLAYACTIVATE {connector}
    Service->>Codec: Parse framed request
    Codec->>Codec: Recognize DISPLAYACTIVATE opcode
    Codec-->>Service: Return operation.display_activate = connector_name
    Service->>Exec: activateDisplayConnector(connector_type)
    Exec->>Output: selectOutputConnector(connector_type)
    Output->>Output: Iterate entries for matching connected connector
    alt Connector found
        Output->>Output: Mutate state fields (scanout, resolution, etc.)
        Output-->>Exec: return true
        Exec-->>Service: Success
    else Connector not found
        Output-->>Exec: return false
        Exec-->>Service: DisplayConnectorMismatch error
    end
    Service->>Output: statePtr() to build response
    Service-->>Client: DISPLAYACTIVATE {connector} scanout=X current=WxH or ERR response