Plan mode is the knowledge-worker's workhorse

The reason Plan modeA mode that makes no edits: it researches the codebase and produces an editable plan you review before any code changes. Press Enter for the full definition. pays off for non-engineers: you carry years of pattern-matching in your head, and the underlying models are smart but don't know how you do your work. So you brain-dump the problem and what good looks like, let the agent research the docs and codebase and write a Markdown plan, correct it, then let it execute and test on a few examples. The modes are worth knowing by name: agent (the default), plan (start a task and scope the approach), ask (read-only, safe for onboarding and analysis), and a meta-agent layer that babysits parallel agents.

A lot of it just came from brain-dumping - the models are so smart, but they often don't understand the way we do our work.

It's a lot easier to build those than it would be to create an interactive prototype with something like Figma, because the agent can just build a fully functioning web app.