# Your AI Agent Says “Done!” — Here’s How to Know If It’s Lying

> Source: <https://pub.towardsai.net/your-ai-agent-says-done-heres-how-to-know-if-it-s-lying-4ad7eddc5865?source=rss----98111c9905da---4>
> Published: 2026-07-16 13:01:04+00:00

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# Your AI Agent Says “Done!” — Here’s How to Know If It’s Lying

A tested, dependency-light tracing and evaluation library that catches the failure mode plain logging can’t — an agent that fails a tool call and confidently reports success anyway.

**Estimated Reading Time:** 17–20 minutes

## Table of Contents

- Introduction
- Problem Statement
- Background
- Core Concepts
- Technology Deep Dive
- Architecture
- Mini Project: TraceBench
- Implementation
- Code Walkthrough
- Testing
- Performance
- Limitations
- Best Practices
- Common Mistakes
- Production Considerations
- Future Improvements
- Conclusion
- Further Reading
- Official References

## Introduction

Picture a pilot’s black box. It doesn’t fly the plane. It doesn’t make the plane safer by itself. What it does is record, second by second, exactly what every system was doing — so that when something goes wrong, nobody has…