Document Pointerbench inference protocol

README.md

@@ -109,6 +109,20 @@ python eval.py --predictions preds.jsonl
 Predictions are JSONL rows with an `id` and either a `point` or `bbox`, depending
 on `answer_type`.
 
+Recommended inference prompt:
+
+```bash
+python eval.py --show-system-prompt
+```
+
+```text
+You are evaluating Pointerbench, a GUI grounding benchmark. You will receive one 1024x768 screenshot and one task instruction. Use absolute pixel coordinates with origin at the top-left of the image. Do not return normalized coordinates. Do not crop or resize the coordinate frame. For point tasks, return JSON like {"point": [x, y]}. For bounding-box tasks, return JSON like {"bbox": [x0, y0, x1, y1]}.
+```
+
+You can edit the prompt for your inference stack. Keep the 1024x768 absolute
+pixel coordinate frame fixed, and report any image resizing or multi-step zoom
+strategy with your results.
+
 See each subset README for the exact distribution, schema details, and examples.
 
 ## License