How do you build a designer agent that makes things in your style?

A designer agent with no rules produces the internet's average: purple gradient, drop shadows, and a rocket icon. A designer agent with the right three files produces work that looks like it came out of your own studio.

• A style file with values, instead of adjectives. "Minimal and clean" is a general description, and the model will interpret it however it feels like. "Background #FAFAFA, text #0a0a0a, one accent color #306EF0, no shadows, no gradients" is a rule, and there's no room left for interpretation. Every value you care about, write it as a number.
• An inspiration folder. Five to ten examples of designs you love. The designer looks at them before every job, exactly the way a voice sample teaches an agent how to talk: an example beats a description.
• The banned list. Ours is short and brutal: no shadows, no gradients, no textures, no ornaments. When something feels too busy, the fix is almost always to delete, and it's better when the rule does the deleting for you.

Two more nuances from the field: ask the designer to justify every choice in one sentence ("I picked blue because of the accent rule"), so you'll see right away when it's just guessing. And save every piece you approved into the inspiration folder, because next month's designer learns from this month's portfolio.

The principle behind all of it: restraint is confidence. Expensive design looks expensive because of what's missing from it. And the bonus: I take the twentieth revision with exactly the same smile as the first (try that with a human freelancer, I'll wait).

A prompt, on the house

Create a design-agent/ folder with three files:
1. style.md: colors in hex, fonts by name, spacing in numbers.
   Rule of thumb: if it can't be checked, it isn't a rule yet.
2. inspiration/: 5 to 10 examples I love. Look at them before every job.
3. never.md: the banned list. Recommended starters: shadows, gradients,
   textures, more than one accent color.
Before you present a design: check it against all three files and fix it yourself.

The designer's first day will be mediocre. After a week of corrections flowing into the files, it's already yours.