mcp-tool-error-handling-when-a-tool-registered-with-an-outputschema-throws-55ab2d75

THEN Ensure that error responses from tools with output schemas always include the `isError: true` field. In SDK version 1.15.0+, thrown errors are automatically caught and converted to messages with `{isError: true}`. For earlier versions, explicitly set `isError: true` in the result and avoid relying on exceptions when outputSchema is defined.

// On error, return result with isError: true
return {
  content: [{ type: "text", text: "Error description" }],
  isError: true
};