How to keep your AI coding agent on track: explore, plan, then build

When people first use an agentic coding tool like Claude Code or Cursor, they tend to type a one-line request and hope. Sometimes it works. Often the agent confidently builds the wrong thing — solving a problem you didn't ask about, touching files you didn't expect, or skipping the edge case that actually mattered.

The fix isn't a smarter model. It's a workflow: explore first, then plan, then build. This is the pattern Anthropic recommends in its official Claude Code best-practices guide, and the same idea applies to any agent that can read your repo before it edits it.

Why jumping straight to code fails

An AI agent works inside a limited context window — the running record of your conversation plus every file it reads and every command it runs. Two things go wrong when you skip planning:

1. The agent guesses at intent. It can't read your mind, so a vague prompt gets a plausible-but-wrong implementation.
2. Mistakes compound silently. Once the agent starts editing, a wrong assumption in step one is buried under ten more changes before you notice.

Separating thinking from doing catches the wrong assumption while it's still cheap to fix — a sentence of correction instead of a 12-file revert.

Step 1: Explore in a read-only mode

Most serious agents now have a mode where they can read and analyze but cannot change anything. In Claude Code it's called plan mode: a read-only state where the agent reads files and answers questions without editing, running state-changing commands, or committing.

Start by asking the agent to understand the code, not change it:

Read /src/auth and explain how we handle sessions and login.
Also look at how we manage environment variables for secrets.

You're building shared context and verifying the agent actually understands your codebase before you trust it to modify it.

Step 2: Ask for a plan, then push on it

Once the agent has explored, ask for a concrete plan before any code:

I want to add Google OAuth login. What files need to change?
What's the session flow? Write a step-by-step plan — don't write code yet.

The agent returns a numbered plan: which files it will touch, the new session flow, where it'll store tokens. Now don't accept the first draft. This is the cheapest moment to course-correct. Push on the gaps:

• "What happens if the OAuth callback fails halfway through?"
• "We already have a refreshToken helper in src/auth/tokens.ts — reuse it instead of writing a new one."
• "Keep this to the login flow only. Don't touch the existing password reset code."

A few minutes refining the plan here saves an hour of untangling a wrong implementation later.

Step 3: Build with a way to verify

Only now do you let the agent write code — and you give it a way to check its own work. The most powerful single addition to any prompt is a verification step the agent can run itself:

Implement the OAuth flow from your plan. Write a test for the callback
handler covering the failure case, run the test suite, and fix any failures.

Without a check it can run — tests, a build, a screenshot to compare — "looks done" is the only signal the agent has, and you become the error detector for every mistake. With a check, the loop closes on its own: the agent writes, runs the test, reads the result, and iterates until it passes. Ask it to show the actual test output rather than just claiming success.

Step 4: Know when to skip the plan

Planning has overhead, and it isn't always worth it. If the change is small and the scope is obvious — fixing a typo, adding a log line, renaming a variable — just ask the agent to do it directly. A good rule of thumb from the Anthropic guide: if you could describe the diff in one sentence, skip the plan. Reserve the explore-plan-build cycle for work that spans multiple files, uses an approach you're unsure about, or touches code you don't know well.

A safety net: course-correct early and use checkpoints

Even with a good plan, agents drift. Two habits keep you in control:

• Interrupt the moment it goes off track. Don't wait for the agent to finish a wrong approach. In Claude Code, Esc stops it mid-action with context preserved so you can redirect.
• Use checkpoints to experiment freely. Claude Code snapshots your files before each change, so you can tell the agent to try something risky, and if it doesn't work, rewind (Esc Esc or /rewind) and try a different approach. (Checkpoints track the agent's own edits, not external processes — they're a convenience, not a replacement for git.)

And if you find yourself correcting the same mistake more than twice, the context is probably polluted with failed attempts. Clear it and restart with a sharper prompt that bakes in what you just learned — a clean session with a better prompt almost always beats a long one full of dead ends.

The takeaway

Explore, plan, build, verify. It feels slower for the first task and pays for itself by the second. You stop getting confident-but-wrong code, and you start getting an agent that builds the thing you actually meant.