add arxiv

README.md

@@ -38,6 +38,30 @@ We study tool interface improvement as a scalable complement to agent fine-tunin
 
 ---
 
+## Paper (arXiv)
+
+This model is released alongside the preprint:
+
+- **Learning to Rewrite Tool Descriptions for Reliable LLM-Agent Tool Use**  
+  Ruocheng Guo, Kaiwen Dong, Xiang Gao, Kamalika Das  
+  arXiv:2602.20426 (2026) — [paper](https://arxiv.org/abs/2602.20426)
+
+### Citation
+
+```bibtex
+@misc{guo2026learningrewritetooldescriptions,
+      title={Learning to Rewrite Tool Descriptions for Reliable LLM-Agent Tool Use}, 
+      author={Ruocheng Guo and Kaiwen Dong and Xiang Gao and Kamalika Das},
+      year={2026},
+      eprint={2602.20426},
+      archivePrefix={arXiv},
+      primaryClass={cs.AI},
+      url={https://arxiv.org/abs/2602.20426}, 
+}
+```
+
+---
+
 ## Recommended prompt (trace-free)
 
 This is the **canonical inference prompt** used for trace-free tool description generation (also available as `tool_prompt.txt` in the `tool-optimizer` repo).