Prefer raw CallToolResult, ReadResourceResult, or GetPromptResult returns. These helpers remain for upgrade compatibility and map to the official wire envelopes.
Create a failed tool result.
Error message shown to the model.
Tool result with isError: true.
isError: true
Prefer { isError: true, content: [{ type: "text", text: message }] }.
{ isError: true, content: [{ type: "text", text: message }] }
Deprecated
Prefer raw CallToolResult, ReadResourceResult, or GetPromptResult returns. These helpers remain for upgrade compatibility and map to the official wire envelopes.