vCX-Hard - Tool Calling (Reasoning): leaderboard
Metric: Tool-Call Accuracy (%). Source: www.retellai.com. 27 models tracked.
Top models
| # | Model | Score |
|---|---|---|
| 1 | GPT-5.5 | 88.3 |
| 2 | Gemini 3.1 Pro (Preview) | 85.9 |
| 3 | Claude Sonnet 4.5 | 85.8 |
| 4 | Gemini 3.5 Flash | 84 |
| 5 | GLM-5.1 | 83.8 |
| 6 | GPT-5.1 | 83.7 |
| 7 | GPT-5 | 83.2 |
| 8 | Gemini 3 Flash | 81.8 |
| 9 | GPT-5.2 | 81.5 |
| 10 | Gemini 2.5 Pro | 80.6 |
| 11 | Claude Sonnet 4.6 | 80.4 |
| 12 | Claude Haiku 4.5 | 79.4 |
| 13 | GPT-5.4 | 77.4 |
| 14 | Gemini 3.1 Flash Lite | 75.8 |
| 15 | GPT-5 Mini | 75.6 |
Interactive version: theaggregate.ai/benchmark?slug=vcx-hard-tool-calling-reasoning · How It Works · Data refreshed daily, snapshot 2026-09-21.