LongFuncEval: Measuring the effectiveness of long context models for function calling

TL;DR

LongFuncEval measures long context models' function call effectiveness, with 7%-85% performance drop.

cs.SE 🔴 Advanced 2025-04-30 5 views
Kiran Kate Tejaswini Pedapati Kinjal Basu Yara Rizk Vijil Chenthamarakshan Subhajit Chaudhury Mayank Agarwal Ibrahim Abdelaziz
long context function calling LLM tool usage performance evaluation

Key Findings

Methodology

This study modifies existing benchmarks and creates a new evaluation set to systematically assess long context models' performance in tool calling. Input context length is gradually increased, and the answer's position is varied to evaluate several long context models.

Key Results

  • Result 1: Performance drops 7% to 85% as tool number increases.
  • Result 2: Answer retrieval degrades 7% to 91% with longer tool responses.
  • Result 3: Multi-turn conversation length increases cause 13% to 40% performance drop.

Significance

This study is the first to comprehensively explore long context models' understanding in tool calling, revealing current models' limitations in handling complex enterprise applications and motivating future LLM improvements.

Technical Contribution

Technical contributions include identifying three key challenges in long context tool calling and designing evaluation setups by extending public benchmarks, demonstrating LLM difficulties in handling long tool responses and multi-turn dialogues.

Novelty

This study is the first to systematically investigate long context tool calling challenges, proposing a new evaluation dataset to assess LLM's ability to handle long tool responses.

Limitations

  • Limitation 1: Significant performance drop when tool number increases, especially in long contexts.
  • Limitation 2: Long tool responses and multi-turn dialogues greatly impact model performance.

Future Work

Future research could explore enhancing LLM's context understanding, particularly in handling long tool responses and complex dialogues.

AI Executive Summary

The effectiveness of long context models in function calling is a crucial research area, especially in enterprise applications. Existing LLMs face challenges in handling long contexts, such as large tool catalogs, lengthy API responses, and complex multi-turn dialogues. This study systematically assesses these models' performance in tool calling by modifying existing benchmarks and creating a new evaluation set. Results show significant performance drops as tool numbers and response lengths increase, highlighting current models' limitations in handling complex enterprise applications. Future research should focus on improving LLM's context understanding to address these challenges.

Deep Analysis

Background

Recent advances in LLMs have shown significant progress in various fields, but challenges remain in handling long contexts. In enterprise applications, LLMs need to manage complex multi-turn dialogues and extensive tool usage.

Core Problem

The core problem is LLM's insufficient ability to call functions in long contexts, specifically with large tool catalogs, lengthy API responses, and complex multi-turn dialogues.

Innovation

This study's innovation lies in systematically investigating long context tool calling challenges for the first time and proposing a new evaluation dataset to assess LLM's ability to handle long tool responses.

Methodology

  • �� Modify existing benchmarks to address long context challenges
  • �� Create a new evaluation set to analyze the impact of tool response length on performance
  • �� Gradually increase input context length to evaluate various long context models

Experiments

The experimental design includes using various long context models, gradually increasing tool numbers and response lengths, and evaluating their performance across different context lengths.

Results

Results indicate significant performance drops as tool numbers and response lengths increase, particularly in long contexts.

Applications

Application scenarios include handling complex tasks in enterprises, such as multi-turn dialogues and extensive tool usage.

Limitations & Outlook

Limitations include significant performance drops in long contexts, necessitating future research to enhance model's context understanding.

Plain Language Accessible to non-experts

Imagine shopping in a large supermarket with thousands of products. You need to find specific items, but they are scattered across different aisles, and the information is chaotic. Long context models are like your shopping assistant, needing to quickly and accurately find what you need in this complex environment. However, as the supermarket grows larger and the product variety increases, the assistant's performance declines. This is the challenge long context models face in handling complex tool calls.

ELI14 Explained like you're 14

Imagine playing a massive multiplayer online game where you need to talk to different characters to get quest information. There are many characters, and the dialogues are long. Long context models are like your game assistant, needing to find key information in these complex dialogues to help you complete quests. But as the dialogues get longer and more characters appear, the assistant becomes less reliable. This is the problem long context models face with complex dialogues!

Glossary

Long Context Model

A language model capable of processing long text inputs, suitable for complex tasks.

Used to evaluate function calling capabilities in long contexts.

Tool Calling

The process of generating function calls in response to user queries.

Evaluating LLM's performance in tool calling within long contexts.

Multi-turn Dialogue

A dialogue involving multiple interactions between user and model.

Evaluating model performance in complex tasks.

API Response

Data returned after a tool call, often in JSON format.

Assessing LLM's ability to handle long tool responses.

Performance Degradation

The phenomenon of model performance declining under specific conditions.

Model performance drops as tool numbers and response lengths increase.

Open Questions Unanswered questions from this research

  • 1 How to improve LLM's tool calling performance in long contexts?
  • 2 What are the limitations of current models in handling complex dialogues?

Applications

Immediate Applications

Enterprise Applications

Handling complex tasks in enterprises, such as multi-turn dialogues and extensive tool usage.

Long-term Vision

Intelligent Assistants

Developing intelligent assistants capable of handling complex contexts to improve work efficiency.

Abstract

Multiple recent studies have documented large language models' (LLMs) performance on calling external tools/functions. Others focused on LLMs' abilities to handle longer context lengths. At the intersection of these areas lies another interesting problem: LLMs' abilities to accurately perform function calls in long context settings. Particularly, when calling tools, LLMs are encumbered by three predominant challenges: (1) a large catalog of tools, (2) long responses from the tool APIs, and (3) long multi-turn conversations. These challenges are particularly relevant to enterprise applications of LLMs which engage in multi-turn conversations with users to complete complex tasks that require a large catalog of complex tools. The literature contains multiple investigations of long context challenges such as lost in the middle or needle in the haystack for natural language tasks. In this paper, we make the first attempt to comprehensively study the long context understanding capabilities of these models in the tool calling setup. We modify existing benchmarks for challenge 1 and 3, and create a new evaluation set for challenge 2 to enable this analysis. We gradually increase the input context length and also vary the position of the answer in the input. When evaluated with several long context models, we observe a performance drop of 7% to 85% as the number of tools increases, a 7% to 91% degradation in answer retrieval as the tool responses length increases, and 13% and 40% degradation for as multi-turn conversations get longer. Our study shows that LLMs still struggle with long context in tool calling settings, motivating future research to drive further LLM improvements.

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