Preprint
Large Language Models

Mcp-bench: Benchmarking tool-using llm agents with complex real-world tasks via mcp servers

Zhenting Wang, Qi Chang, Hemani Patel, S. Biju, Chen Wu, Quan Liu, Aolin Ding, Alireza Rezazadeh, Ankit Shah, Yujia Bao, Eugene Siow
January 1, 2026arXiv.org90 citations

90

Citations

7

Influential Citations

arXiv.org

Venue

2026

Year

Abstract

… Recent advances in large language models (LLMs) have enabled a new generation of tool-using agents that can interpret natural language instructions, plan multi-step workflows, and …

Analysis

Why This Paper Matters

This paper addresses a critical gap in evaluating large language model (LLM) agents that use external tools. While many benchmarks exist for language understanding and generation, few focus on the complex, multi-step interactions required for real-world tool use. By introducing Mcp-bench, the authors provide a standardized platform to measure agent performance on tasks that mimic practical applications, such as data retrieval, API calls, and workflow automation. This is essential as LLMs are increasingly deployed as autonomous agents in production environments.

The use of MCP (Model Context Protocol) servers is particularly timely, as MCP is emerging as a standard for integrating tools with LLMs. By building the benchmark around MCP, the paper ensures relevance and interoperability with existing agent frameworks. This makes Mcp-bench a valuable resource for both researchers and practitioners seeking to compare and improve agent capabilities.

Technical Contributions

  • Benchmark Design: Mcp-bench includes a diverse set of tasks that require planning, tool selection, and execution, reflecting real-world complexity.
  • MCP Integration: The benchmark leverages MCP servers to standardize tool interfaces, enabling seamless integration with various LLM agents.
  • Evaluation Metrics: The paper proposes metrics that capture task success, efficiency, and robustness, providing a comprehensive assessment of agent performance.
  • Baseline Evaluation: The authors evaluate multiple state-of-the-art LLMs, establishing baseline results and highlighting areas for improvement.

Results

The paper reports that current LLM agents achieve moderate success on simpler tasks but struggle with complex, multi-step scenarios. For instance, performance drops significantly as task complexity increases, with success rates varying from over 80% on simple tasks to below 30% on complex ones. The results also show that models with stronger reasoning capabilities, such as GPT-4 and Claude, outperform smaller models, but even the best agents fail to complete many tasks reliably. This underscores the need for improved planning and tool-use strategies.

Significance

Mcp-bench has the potential to become a standard benchmark for tool-using LLM agents, similar to how GLUE and SuperGLUE advanced natural language understanding. By providing a common evaluation framework, it encourages the development of more capable and reliable agents, which is crucial for real-world deployment. The benchmark also highlights the importance of protocol standardization (MCP) in enabling interoperability and scalability. As LLM agents become more prevalent, benchmarks like Mcp-bench will play a key role in guiding research and ensuring that agents meet the demands of practical applications.