Documentation Debt Compounds Faster Than Code Debt

README.md: Last updated 47 commits ago.

The codebase has moved on. The docs haven't. Somewhere between "ship it" and "we'll fix that later," the documentation started describing a system that no longer exists.

The drift

You onboard a new engineer. They read the README. They follow the setup instructions. Nothing works the way the docs describe.

Two hours later, they find you on Slack: "Is this README current?"

It isn't. It was accurate on round one, when you generated it with an AI assistant. Then you shipped six more features. Renamed three modules. Refactored the auth flow. The docs stayed frozen in time.

This is documentation debt, and it compounds faster than code debt. Code debt announces itself: tests fail, builds break, errors surface. Documentation debt stays silent until someone trips over it. Usually a new hire. Usually at the worst possible moment.

The pattern that causes it

AI-assisted development makes this worse before it makes it better.

The agent generates clean documentation on the first pass. You review it, approve it, merge it. The docs look professional. You feel organized.

Then you iterate. You prompt the agent to fix a bug. Add a feature. Refactor a slow path. Each change updates the code. None of them update the docs.

"There's been too many times I've missed that and then the documentation that was created maybe on round one and then I do a bunch of things and forget to do that along the way and then it has resulted in my documentation being completely out of date."

Matthew Rudolph, After Hours S01E02

The problem isn't that the agent can't update docs. It can. The problem is that you didn't ask it to.

The fix: docs in the loop

The teams that avoid documentation drift do one thing differently: they include documentation updates in the prompt itself.

Not as an afterthought. Not as a separate task. As part of the work definition.

"I include that stuff in the prompt. Like when I'm getting orchestrator mode going, I say, Hey, look at the dev plan. I want you to follow the dev plan. Update it as you go along so another AI coding assistant can step in and know where to continue working and to update documentation as features are added and as bugs are fixed."

Ru Tang, After Hours S01E02

The key insight: documentation is a handoff artifact. It isn't just for humans reading it later. It's for the next AI session that picks up where you left off. If the docs are stale, the next agent starts with wrong assumptions. The loop breaks before it begins.

The tradeoff

Including documentation updates in every prompt adds overhead. The task runs slightly longer. The diff includes more files. Your review surface grows.

But the alternative is a catch-up sprint you'll never schedule. Documentation debt doesn't announce itself until onboarding stalls, handoffs fail, or a new contributor spends a day debugging setup instructions that no longer apply.

The overhead of "update docs as you go" is predictable. The cost of "we'll document it later" is unbounded.

How Roo Code closes the loop on documentation

Roo Code is an AI coding agent that closes the loop: it proposes diffs, runs commands and tests, and iterates based on results. This same capability applies directly to documentation maintenance.

When you include documentation updates in your task prompt, Roo Code treats docs as part of the deliverable. The agent reads existing documentation, identifies what changed in the code, and updates the relevant files in the same diff. You review code and docs together, approve once, and merge a complete change.

With BYOK (bring your own key), you control the model and context. Your documentation stays in your environment, updated by an agent that sees both the code changes and the existing docs in the same session. No context fragmentation. No separate documentation sprint.

Roo Code prevents documentation debt by keeping docs in the same iteration loop as code, so every feature ships with accurate documentation.

Documentation approaches compared

Why this matters for your team

For a Series A - C team shipping weekly, documentation drift compounds in weeks, not months. Every feature that ships without a docs update is a liability for the next hire, the next handoff, the next AI session.

The compounding works both ways. If the agent updates docs on every pass, knowledge stays current. Onboarding stays fast. Handoffs stay clean. The next person (or the next agent) starts with accurate context instead of archaeological guesswork.

The prompt addition

Add one line to your task prompts: "Update relevant documentation as features are added and bugs are fixed."

That's it. One instruction. The agent treats documentation as part of the deliverable, not as a follow-up you'll forget to schedule.

The docs stay in sync. The debt stops compounding.