---
language:
- en
- zh
license: apache-2.0
library_name: transformers
base_model: Qwen/Qwen3-8B
tags:
- qwen3
- tool-use
- mcp
- code-generation
- sft
datasets:
- tool-genesis/Tool-Genesis-Benchmark
pipeline_tag: text-generation
model-index:
- name: Tool-Genesis-Qwen3-8B-SFT
  results:
  - task:
      type: text-generation
      name: MCP Server Generation (Direct)
    dataset:
      name: Tool-Genesis Benchmark
      type: tool-genesis/Tool-Genesis-Benchmark
    metrics:
    - type: compliance
      value: 0.826
      name: L1 Compliance
    - type: launch_rate
      value: 0.047
      name: L1 Launch Rate
    - type: schema_f1
      value: 0.046
      name: L2 Schema F1
    - type: ut_soft
      value: 0.017
      name: L2 UT Soft
---

# Tool-Genesis-Qwen3-8B-SFT

A fine-tuned [Qwen3-8B](https://huggingface.co/Qwen/Qwen3-8B) model for autonomous MCP (Model Context Protocol) tool server generation. Given a natural language scenario description, the model generates a complete, runnable MCP server with tool schemas and implementation code.

## Model Details

| Property | Value |
|---|---|
| Base model | [Qwen/Qwen3-8B](https://huggingface.co/Qwen/Qwen3-8B) |
| Architecture | Qwen3ForCausalLM |
| Parameters | 8B |
| Hidden size | 4096 |
| Layers | 36 |
| Attention heads | 32 |
| Context length | 131,072 tokens |
| Training method | Full-parameter SFT |
| Training epochs | 3 |
| Training steps | 117 |
| Training loss | 0.522 |
| Training data | ~2,500 samples |

## Training

The model was fine-tuned on curated MCP server generation examples from the Tool-Genesis benchmark. Each training sample consists of:

- **Input**: A natural language scenario description specifying what the MCP server should do
- **Output**: A complete Python MCP server implementation using the FastMCP framework

### Training Configuration

- **Epochs**: 3
- **Total steps**: 117 (~39 steps/epoch)
- **Final training loss**: 0.522
- **Training runtime**: ~4.6 hours

### Loss Curve

| Step | Loss |
|---|---|
| 1 | 0.763 |
| 10 | 0.690 |
| 20 | 0.641 |
| 39 (epoch 1) | 0.539 |
| 60 | 0.434 |
| 78 (epoch 2) | 0.436 |
| 100 | 0.420 |
| 117 (epoch 3) | 0.522 |

## Benchmark Results

Evaluated on the [Tool-Genesis Benchmark](https://huggingface.co/datasets/tool-genesis/Tool-Genesis-Benchmark) (86 MCP servers, 4-level evaluation).

### Direct Generation (single-call, no agent loop)

| Model | L1 Compliance | L1 Launch | L2 Schema F1 | L2 UT Soft |
|---|---|---|---|---|
| Qwen3-8B (base) | 0.686 | 0.012 | 0.011 | 0.001 |
| **Qwen3-8B-SFT (ours)** | **0.826** | **0.047** | **0.046** | **0.017** |
| Qwen3-235B | 0.874 | 0.333 | 0.316 | 0.142 |
| GPT-4.1 | 0.881 | 0.738 | 0.691 | 0.267 |
| GPT-5.1 | 0.855 | 0.759 | 0.713 | 0.291 |

**SFT gains over base Qwen3-8B (Direct):**
- L1 Compliance: +14.0% (0.686 → 0.826)
- L1 Launch: +3.5% (0.012 → 0.047)
- L2 Schema F1: +3.5% (0.011 → 0.046)
- L2 UT Soft: +1.6% (0.001 → 0.017)

### With Coder-Agent (multi-turn with sandbox)

| Model | L1 Compliance | L1 Launch | L2 Schema F1 | L2 UT Soft |
|---|---|---|---|---|
| Qwen3-8B (base, coder-agent) | 0.776 | 0.694 | 0.653 | 0.246 |
| Qwen3-235B (coder-agent) | 0.868 | 0.971 | 0.914 | 0.459 |
| GPT-4.1 (coder-agent) | 0.884 | 0.756 | 0.691 | 0.288 |
| GPT-5.1 (coder-agent) | 0.906 | 0.941 | 0.877 | 0.426 |

> Note: The coder-agent strategy dramatically improves all models by providing an iterative sandbox-based coding loop. The SFT model has not yet been evaluated with the coder-agent strategy.

## Usage

```python
from transformers import AutoModelForCausalLM, AutoTokenizer

model_name = "tool-genesis/Tool-Genesis-Qwen3-8B-SFT"
tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(model_name, torch_dtype="auto", device_map="auto")

prompt = """You are a developer building MCP tool servers in Python.
Build a complete MCP server for the following scenario:

A weather information service that provides current weather data, 
forecasts, and weather alerts for any location worldwide.

Output only the Python source code using the FastMCP framework."""

inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
outputs = model.generate(**inputs, max_new_tokens=4096, temperature=0.2)
print(tokenizer.decode(outputs[0], skip_special_tokens=True))
```

## Evaluation Protocol

The Tool-Genesis benchmark evaluates generated MCP servers across four levels:

| Level | What it tests |
|---|---|
| **L1: Protocol Compliance** | JSON format validity and server launch success |
| **L2: Semantic Correctness** | Tool schema matching (F1) and unit test pass rate |
| **L3: Capability Boundary** | No unauthorized capabilities or dangerous extra tools |
| **L4: Task Utility** | Downstream task completion using generated tools |

## Links

- **Benchmark Dataset**: [tool-genesis/Tool-Genesis-Benchmark](https://huggingface.co/datasets/tool-genesis/Tool-Genesis-Benchmark)
- **Code**: [github.com/Tool-Genesis/Tool-Genesis](https://github.com/Tool-Genesis/Tool-Genesis)

## Citation

```bibtex
@misc{tool_genesis_2025,
  title={Tool-Genesis: A Task-Driven Tool Creation Benchmark for Self-Evolving Language Agent},
  author={Xia, Bowei and Hu, Mengkang and Wang, Shijian and Jin, Jiarui and Jiao, Wenxiang and Lu, Yuan and Li, Kexin and Luo, Ping},
  year={2025},
  note={Project page: https://tool-genesis.github.io}
}
```

## License

Apache 2.0