EgoTools: Towards Tool-Centric Reasoning in Real-World Egocentric Videos

Shulin Tian, Junsu Kim, Shuai Liu, Hao Li, Yujiao Shen, Sihan Li, Zhe Yang, Yeongon Kim and 12 others

S-Lab, Nanyang Technological University · A*STAR · KAIST · PKU · FDU · University of Catania

Published September 30, 2026 · on the feed October 2, 2026 · ▲ 60 · arXiv 2609.39378

The abstract

Real-world embodied tasks, from everyday activities to professional procedures, require agents to act under physical constraints while tracking evolving object and task states. Tool use sits at the heart of such tasks, as many everyday and professional activities are tool-mediated. Understanding them requires reasoning about affordances, hand-tool-object geometry, procedural progress, and causal effects on target objects. Yet despite strong performance on perception-oriented video tasks such as captioning and general video QA, current multimodal video models remain limited in this form of tool-centric embodied reasoning. Progress in this direction has been limited by the lack of real-world egocentric data and diagnostic benchmarks. To address this gap, we introduce EgoTools, the first comprehensive suite for egocentric tool-use understanding. It consists of two complementary components: EgoTools-Data, a large-scale corpus of 100 hours of tool-centric egocentric recordings with synchronized audio, dense captions, reasoning-heavy narrations, and supplementary 3D information; and EgoTools-Bench, a diagnostic benchmark of 1,000 QA pairs across four tracks that cover tool-use understanding from perception and geometry to procedure and causal reasoning. Experimental results show that current models still struggle to ground tool use in visual evidence: Gemini-3.1-Pro achieves 66.9% overall accuracy but only 51.7% on Perception & Grounding. Beyond evaluation, we validate EgoTools-Data as a training resource. On the full 1,000-question benchmark, full supervised fine-tuning improves Qwen3-VL-8B-Instruct from 50.0% to 60.9%, under strict source-video separation. Together, these results establish EgoTools as a unified resource for both training and diagnostic evaluation of real-world egocentric tool-use understanding.

The Brief

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Transcript

EgoTools. Towards Tool-Centric Reasoning in Real-World Egocentric Videos. By Shulin Tian and nineteen others, from S-Lab at Nanyang Technological University, A-STAR, and four other institutions. Published on the thirtieth of September. Its code repository is worked out: about seventy-five source files, with a readme.

EgoTools is a suite for understanding tool use in egocentric video, which the authors describe as the first comprehensive one of its kind. The motivation is that real embodied tasks, from everyday activities to professional procedures, ask an agent to act under physical constraints while tracking how objects and task states evolve, and that many of those activities are mediated by tools. Understanding them means reasoning about affordances, about the geometry between hand, tool and object, about procedural progress, and about causal effects on the target object. Current multimodal video models do well on perception-oriented tasks such as captioning and general video question answering, yet remain limited at this kind of tool-centric reasoning, and the authors trace slow progress to a lack of real-world egocentric data and diagnostic benchmarks.

The suite has two complementary parts. EgoTools-Data is a large-scale corpus of one hundred hours of tool-centric egocentric recordings. They come with synchronized audio, dense captions, narrations heavy in reasoning, and supplementary 3D information.

EgoTools-Bench is a diagnostic benchmark of one thousand question and answer pairs, arranged in four tracks. Together the tracks run from perception and geometry through to procedure and causal reasoning.

Both parts are built from real-world egocentric recordings of tool use, captured from the wearer's own point of view. The benchmark results show what it diagnoses. Current models still struggle to ground tool use in visual evidence: Gemini three point one Pro reaches sixty-six point nine percent overall accuracy, but only fifty-one point seven percent on the Perception and Grounding track.

Two audiences are served. Anyone evaluating video models on embodied tool use gets a benchmark that separates perception from procedure and causation. Anyone training such models gets data, and the authors validate that use directly. On the full thousand-question benchmark, supervised fine-tuning of Qwen three VL eight B Instruct on EgoTools-Data lifts accuracy from fifty point zero percent to sixty point nine percent, with the source videos strictly separated between training and evaluation.

The strict separation is what makes that last number meaningful: the gain is not the model having seen the test videos. One corpus and one benchmark, drawn from the same recordings, are offered as a single resource for both training and diagnosis of tool-use understanding in egocentric video.

Paper Quest · 7 chapters · about 40 min

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Learn it by doing: make the calls the authors made, guess the result before you see it, and defend it in a viva graded on your own words. Chapter 1 is right here.

Chapter 1 🧩 · The problem

Models can name what they see. Ask them how a tool did its job, and the picture changes.

You are testing video models on footage filmed from a worker's head camera: someone trims asparagus, tries scissors, then switches to a knife. The models caption scenes well and answer general video questions with ease.

The road ahead

  1. 1 · The problem ~7 min Video models describe first-person footage well, yet stumble when asked why a tool was chosen or how it touched the object.
  2. 2 · What came before ~3 min
  3. 3 · The key idea ~8 min Record real tool use from the wearer's view, annotate why tools are used, test models in four separate tracks, and train on the same data.
  4. 4 · Choose your own research ~3 min
  5. 5 · Build the method ~8 min Record tool use, annotate it, build a four-track benchmark from held-out videos, test current models, then fine-tune one on the rest.
  6. 6 · The experiment ~6 min You’ll guess: Gemini-3.1-Pro reaches 66.9% overall on the new tool-use benchmark. How does it do on the Perception & Grounding track?
  7. 7 · The viva ~5 min Three questions from the examiners, answered in your own words. Win it for the paper’s trophy.
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