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Benchmarks

The benchmark that uses your tools: toolcalling.ai

Static benchmarks can't tell you how a model handles your schema, your users, and your edge cases. At toolcalling.ai, two anonymous models answer the same real tool-calling task in the Arena and you vote for the better one. The blind pairwise votes build a live, real-world leaderboard.

Vote in the Arena See the leaderboard

Public benchmarks

Links checked 2026-11-01.

Function calling

Benchmark Measures
BFCL V4 (Berkeley Function Calling Leaderboard) · code · data · paper The de facto standard: AST-checked single and parallel calls, multi-turn stateful calls, irrelevance/abstention, and agentic tasks (web search, memory, format sensitivity). V3 blog · V4 blog
Nexus Function Calling Leaderboard Zero-shot calls to real-world APIs
NESTFUL Nested call sequences where one call's output feeds the next
ComplexFuncBench Multi-step, constrained calls with long context
ACEBench Normal, special (incomplete or ill-formed requests), and agent cases; EN/ZH
When2Call Deciding between call, ask a follow-up, or say it can't answer
HammerBench Fine-grained function calling in mobile-assistant scenarios
Seal-Tools Self-instruct tools, including nested calls
T-Eval Step-by-step: instruct, plan, reason, retrieve, understand, review
API-Bank 73 runnable APIs in dialogue: planning, retrieval, calling
ToolHop Multi-hop tool use

Agentic / multi-turn

Benchmark Measures
τ-bench · τ²-bench · τ³-bench · leaderboard Agent + simulated user + tools + domain policies (retail, airline, telecom). Reports pass^k reliability
ToolSandbox Stateful, conversational, interactive evaluation
ToolBench / ToolEval · StableToolBench 16k+ real APIs, pass/win rate; StableToolBench makes it reproducible
TaskBench Tool-graph task decomposition and calling
AgentBench Broad agent evaluation across 8 environments

MCP

Benchmark Measures
MCP-Atlas · leaderboard 36 real MCP servers, 220 tools, 1,000 tasks
MCP-Bench 28 live servers, ~250 tools, multi-server planning
MCP-Universe · site Real servers across maps, finance, browser, repos, and more
MCPMark · leaderboard Realistic create/read/update/delete workflows (Notion, GitHub, Postgres, Playwright, filesystem)
LiveMCPBench Navigating a large pool of MCP tools

General-purpose leaderboards (secondary)

These rank models on general chat, coding, or vision preference, not on tool calling specifically. They're useful context when choosing a base model.

Leaderboard Notes
LMArena (now Arena) Large-scale blind pairwise human votes on general prompts. Formerly Chatbot Arena; renamed Arena in January 2026 (announcement)

For tool calling, prefer the function-calling and agentic benchmarks above and the toolcalling.ai leaderboard.

Reading benchmark results

  • Match the benchmark to your use. Single-call AST scores say little about 20-step agents, and the reverse is true too.
  • Look at the sub-scores: irrelevance, multi-turn, and long context often differ far more than the overall score.
  • pass^k beats pass@1 for production: users don't retry.
  • Contamination: public test sets leak into training data. Keep a private eval (Evaluation).
  • Format sensitivity: the same model scores differently with prompt-based vs native tool calling.
  • Then validate on your own tools in the toolcalling.ai workspace, and check the community leaderboard.