tweak end_turn prompt examples

Author: charleslien

backend/src/tools/definitions/tool/end-turn.ts

@@ -13,7 +13,15 @@ Only use this tool to hand control back to the user.
 - Before calling: finish all pending steps, resolve tool results, and include any outputs the user needs to review.
 - Effect: Signals the UI to wait for the user's reply; any pending tool results will be ignored.
 
-Correct usage:
+*INCORRECT USAGE*:
+${getToolCallString('some_tool_that_produces_results', { query: 'some example search term' }, false)}
+
 ${getToolCallString(toolName, {})}
+
+*CORRECT USAGE*:
+All done! Would you like some more help with xyz?
+
+${getToolCallString(toolName, {})}
+
     `.trim(),
 } satisfies ToolDescription