💬 Ask

You want understanding, not changes.

• Explain what this function does or why it was written this way
• Review code for bugs, smells, or security issues
• Compare two approaches before committing to one
• Generate a snippet you’ll paste and review yourself
• Onboard to an unfamiliar codebase — “walk me through this flow”

🗺️ Plan

You want a blueprint before the AI touches anything.

• Non-trivial features that span multiple files or systems
• Risky refactors where a wrong assumption is expensive to undo
• Situations where you need to approve the approach first
• Architecture decisions — let AI surface tradeoffs, you decide
• Starting a new module: “plan how to add auth to this app”

🤖 Agent

You want it done — and you trust the scope.

• Well-scoped tasks with a clear finish line: “add dark mode to this component”
• Mechanical work you’d find tedious: writing tests, adding JSDoc, migrations
• Iterating on a plan you already approved in Plan mode
• Chained edits across many files that follow an obvious pattern

TL;DR

Most people jump to Agent by default. The real power move is using Plan for anything non-trivial — it forces alignment before the AI writes a single line, and saves you a painful revert 20 minutes later.