Best LLM for Function Calling / Tool Use
Ranked on tool-selection accuracy, multi-tool consistency, and price. Tool-use quality compounds in agent loops.
Updated April 2026. Top 3 this month: DeepSeek: R1 0528, Qwen: Qwen3.5 Plus 2026-02-15, DeepSeek: DeepSeek V3.
How we rank
Function calling is the connective tissue of agent systems. A model that picks the wrong tool once in 20 calls is unacceptable for any non-trivial automation. We weight tool-selection accuracy and multi-tool benchmarks heavily, then price.
Pillars and weights: tool selection (45%) · multi-tool (30%) · price (25%). Our full methodology is published on the methodology page.
Top ranked models
| Rank | Model | Provider | Input $/1M | Output $/1M | Context |
|---|---|---|---|---|---|
| 1 | DeepSeek: R1 0528 | DeepSeek | $0.50 | $2.15 | 163,840 |
| 2 | Qwen: Qwen3.5 Plus 2026-02-15 | Qwen | $0.26 | $1.56 | 1,000,000 |
| 3 | DeepSeek: DeepSeek V3 | DeepSeek | $0.32 | $0.89 | 163,840 |
| 4 | Qwen: Qwen3.5 397B A17B | Qwen | $0.39 | $2.34 | 262,144 |
| 5 | Tencent: Hunyuan A13B Instruct | Tencent | $0.14 | $0.57 | 131,072 |
| 6 | MiniMax: MiniMax M2.1 | MiniMax | $0.29 | $0.95 | 196,608 |
| 7 | Arcee AI: Trinity Large Preview | Arcee AI | $0.00 | $0.00 | 131,000 |
| 8 | OpenAI: GPT-4o (2024-11-20) | OpenAI | $2.50 | $10.00 | 128,000 |
| 9 | MiniMax: MiniMax-01 | MiniMax | $0.20 | $1.10 | 1,000,192 |
| 10 | Anthropic: Claude Sonnet 4.5 | Anthropic | $3.00 | $15.00 | 1,000,000 |
Tips for function calling / tool use
- Keep the tool list short and well-named. Long tool lists degrade accuracy.
- Use JSON schemas with required fields to reduce malformed calls.
- Log tool failures and retry with a fallback model tier if needed.
Frequently asked questions
Which LLM is best at tool use?
As of April 2026, our weighted top 3 are DeepSeek: R1 0528, Qwen: Qwen3.5 Plus 2026-02-15, DeepSeek: DeepSeek V3.
How many tools is too many?
Accuracy drops noticeably past ~30 tools in a single call. Route to a smaller toolset per conversation turn when you can.
Are tool-use benchmarks trustworthy?
Directionally yes — run the top 2 on your actual tool catalog before committing.
Related tasks
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Data refreshed daily via our snapshot cron. See our public JSON API for programmatic access.