The Agent Rewrote Code That Already Worked

Developing with AI assistants often feels like a superpower until it results in a regression. A common frustration occurs when an agent rewrote code that already worked, replacing a functional logic block with something broken or unnecessarily complex. This failure mode happens because LLMs prioritize token prediction over state preservation. When an agent loses the context of why a specific piece of code exists, it tends to refactor it into a hallucinated ideal state. Understanding why this occurs is the first step toward building a more resilient development workflow.

Why Agents Refactor Functional Logic

The tendency for an agent to rewrite working code usually stems from a mismatch between the prompt instructions and the current file state. Most coding agents operate on a cycle of reading, thinking, and editing. If the reading phase fails to capture the subtle dependencies of a function, the thinking phase assumes the code is "cruft" or boilerplate that needs optimization.

Lack of Intent Awareness

Agents lack a long term memory of your architectural decisions. They see the code as it exists in the current buffer. If you have a specific performance optimization that looks unconventional, the agent might interpret it as a bug. Without explicit comments or a history of the previous successful execution, the agent defaults to the most probable patterns found in its training data, which often erases specialized logic.

Context Window Drift

As a session grows longer, the older parts of the conversation fall out of the context window. The agent might forget that you specifically asked for a certain implementation five prompts ago. When it revisits that file to add a new feature, it sees the old code as something it can "improve" to fit the new requirements, leading to a silent rewrite of a stable feature.

Comparing Agent Architectures

Different AI tools approach the problem of code preservation in various ways. Some focus on strict diffing, while others allow the agent more creative freedom.

Monitoring Agents with Deska

When using tools like Claude Code, Codex CLI, or OpenCode, visibility is the best defense against unwanted rewrites. Deska provides an infinite canvas where you can run these agents side by side as panels. This allows you to monitor exactly what each agent is doing in real time.

You can place your code editor panel right next to your terminal panels. When an agent attempts a rewrite, the changes are visible in the Monaco-based editor instantly. If you notice that an agent rewrote code that already worked, you can use the ask-deska assistant to intervene. You can ask Deska to stop a process or revert a specific file change through the command palette.

Using the Infinite Canvas for Context

The canvas layout helps prevent regressions by keeping documentation and notes visible. By keeping a notes panel open with your core architectural rules, you can quickly copy-paste constraints into the agent's prompt. This physical organization of information reduces the chance of the agent making assumptions about your codebase.

Strategies to Prevent AI Regressions

To stop an agent from destroying functional code, you must implement a workflow that emphasizes verification over automation.

• Use granular commits. Before starting a task with an agent, commit your working state. This makes it trivial to diff the agent's output.
• Write "Protective" tests. If a piece of code is critical, ensure there is a unit test for it. Run these tests in a terminal panel after every agent intervention.
• Limit the scope. Instead of asking an agent to "refactor the project," ask it to "modify the export logic in file X." Smaller scopes reduce the chance of the agent wandering into unrelated functional code.
• Leverage local context. Using a local-first approach ensures that the agent has access to your local files without the latency or security risks of uploading entire directories to a cloud environment.

The Role of Multi-Agent Orchestration

Sometimes the best way to verify an agent is to use another agent. In Deska, you can have Claude Code working on a feature while OpenCode reviews the diff in a separate panel. This cross-verification makes it much harder for a single agent to silently break a working system. Because Deska runs these as coding-agents in a shared workspace, they all have access to the same local file system.

Mobile Monitoring and Remote Access

If you are running a long-running agent task, you do not have to stay glued to your desk to ensure it does not break anything. The Deska mobile app allows you to monitor your terminal panels through a secure relay. You can see the logs as the agent works. If you see a sequence of deletes that looks suspicious, you can pause the session from your phone. This direct pairing between devices ensures your data stays private while giving you the freedom to move around.

FAQ

Why did my AI agent delete my comments?

AI agents often view comments as non-essential tokens. If the agent is trying to stay within a specific output limit, it may strip comments to save space or because its training data suggests "cleaner" code has fewer comments. To prevent this, include a specific instruction in your system prompt to preserve all existing documentation and comments.

How do I revert changes if an agent breaks my build?

The most reliable way is using Git through a terminal panel. If you are using Deska, you can quickly open a terminal next to your code and run git checkout . to undo the agent's mistakes. Always ensure you have a clean working directory before letting an agent write to your files.

Can I limit an agent to specific files?

Yes, most agents allow you to specify a file path or a context window. In the Deska workspace, you can manage these permissions by only opening relevant files in the panels currently active. By limiting the "sight" of the agent, you protect the rest of your codebase from accidental rewrites.

Get Started with Deska

If you are tired of losing progress because an agent rewrote code that already worked, it is time to change your environment. Deska offers a local-first, high-visibility workspace designed for the agentic era of software development. You can download the app for Mac, Windows, or Linux and start building with more control.

Visit the download page to get the free desktop application and organize your AI agents on an infinite canvas today.