# POST /mcp -- tools/call lookup_order, an order ID that does not exist

Request:

{"jsonrpc":"2.0","id":6,"method":"tools/call","params":{"name":"lookup_order","arguments":{"orderId":"ORD-9999"}}}

Response (200), note isError:true inside a 200 -- HTTP itself never fails for a tool error:

id:59682b84-e49c-42d2-908e-a8105aa31514
event:message
data:{"jsonrpc":"2.0","id":6,"result":{"content":[{"type":"text","text":"No order with ID ORD-9999\nNo order with ID ORD-9999"}],"isError":true}}