How to Prompt Claude Code (It's Not What You Think)

Drop the ChatGPT habits.

"Act as a senior engineer." "Think step by step." "First analyze the codebase architecture, then identify the best design pattern..." These prompting tricks work fine in ChatGPT. They don't help in Claude Code. Mostly they just burn tokens.

Here's what actually matters: your CLAUDE.md does 80% of the prompting work. It tells Claude Code your stack, your patterns, your coding style, your constraints. The prompt you type is just the task. Not the context. Not the persona. Just: what do you need right now?

The Three Rules of Good Prompts

Rule 1: Be specific about the outcome.

Not "improve the dashboard" but "add a bar chart showing monthly revenue to the analytics dashboard using recharts." Claude Code needs a concrete target, not a direction. Vague goals produce mediocre results and extra back-and-forth.

Rule 2: Reference existing code.

"Make the settings page work like the profile page" is worth more than a paragraph explaining your preferred layout. Claude Code reads your codebase. Use that. Point at things that already exist.

Rule 3: Set the boundaries.

"Add error handling to the checkout flow. Don't change the payment provider integration." Telling Claude Code what NOT to touch is often more valuable than explaining what to do. Scope is everything. Without it, things sprawl.

The "Spec Dump" Mistake

I see this constantly. Someone pastes an entire PRD into a single prompt. 2,000 words of requirements, acceptance criteria, edge cases, API contracts. All at once.

What happens? Claude Code tries to do everything at once. It misses details. It makes contradictory choices. It burns through your context window and delivers something half-right that takes longer to fix than if you'd broken it down.

Prompt Patterns That Work

The fix prompt: "The checkout page returns 500 when the cart is empty. Fix it." Clear problem. Testable outcome. Nothing ambiguous.

The add prompt: "Add pagination to the /api/posts endpoint. 20 items per page, cursor-based." Specific feature, concrete parameters. Claude Code knows exactly what done looks like.

The refactor prompt: "Extract the validation logic from UserForm into a shared useValidation hook. Keep the same tests passing." Clear scope with a safety constraint. The "keep tests passing" part is important. It sets a quality bar.

The investigate prompt: "Why does the search take 3 seconds on pages with 100+ results? Don't fix it yet, just explain." Separating investigation from action is underrated. You get the diagnosis first, and you decide whether the proposed fix is worth it before Claude Code touches anything.

What Makes a Bad Prompt

Too vague: "Make it better." Better how? Faster? More accessible? Cheaper to run? Pick one.

Too broad: "Build the entire user management system." Break it into pieces. Every time.

Too prescriptive: "Create a file called utils/auth.ts, export a function called validateToken that takes a string parameter named token..." At that point you're writing pseudocode. Tell Claude Code what you need it to do, not how to type it.

Redundant with CLAUDE.md: "Use TypeScript, follow our ESLint rules, use Tailwind for styling." If it's already in your CLAUDE.md, repeating it in every prompt wastes tokens and clutters your prompts. The whole point of CLAUDE.md is to avoid this.

The Prompt Quality Checklist

Before you hit Enter:

• Does it describe what you want, not how to do it?
• Is it scoped to one logical task?
• Does it reference existing code or patterns when relevant?
• Are the boundaries clear: what to change and what not to change?
• Is it something CLAUDE.md doesn't already cover?

Five yes answers. Ship it.