Custom Instructions
Facts vs. behavior.
The reference files you built last lesson tell Cowork about your family and you — facts. Custom Instructions tell Cowork how to behave when working inside this Project — behavior. Different jobs, both important.
The two kinds of guidance
- Reference files (last lesson): "My kids are Aiden, Mia, and Liam. Aiden is 9, has a peanut allergy, goes to Lincoln Elementary." That's information.
- Custom Instructions (this lesson): "When I ask for a meal plan, default to five dinners, max 30 minutes cook time, and pull from what's in the pantry first. Format the output as a table." That's how to act.
Custom Instructions live at the Project level. They're a set of standing rules Cowork follows for every conversation in Family Manager. Set them once, refine over time.
Draft them with Cowork.
You could write Custom Instructions from scratch by listing rules, but a faster way is to tell Cowork to interview you about how you want Family Manager to behave, then have Cowork draft the instructions for you to review.
In Family Manager, send this:
Cowork interviews you, then drafts the instructions. Read what it drafted before saving.
Read the draft critically.
The first draft will be close but probably not perfect. Cowork is good at structuring rules but doesn't know your taste yet. Things to watch for in the draft:
- Does the tone match how you'd actually want to be talked to?
- Are there rules that sound generic ("be helpful and friendly") instead of specific to you?
- Is anything missing — a rule you want that didn't come up in the interview?
Tell Cowork what to revise. Iterate until the draft sounds like rules you'd write if you knew how to write good rules.
Save them to the Project.
Once you're happy with the draft, tell Cowork to save it as the Project's actual Custom Instructions:
Cowork saves them at the Project level. They'll be active in every chat you have inside Family Manager from now on.
If you want to see them later
Cowork's Project settings show the Custom Instructions for any Project. You can edit them by hand there, or — easier — tell Cowork what to change:
- "Update my Family Manager Custom Instructions — I want default responses to be even shorter."
- "Add a new rule to my Custom Instructions: when I ask about meal planning, always show the calorie count and prep time per meal."
Cowork updates the instructions and saves. Next chat in Family Manager, the new rule is in play.
Test that they took.
Quick test to confirm Cowork's behavior actually changed. Start a new chat in Family Manager (the new-chat-when-topics-change habit from the folder lesson) and ask something simple that would expose the rules — tone, format, length.
Watch how Cowork answers. Does the tone match your Mom Profile? Is the format what you said you wanted? Is the length appropriate? If yes, your Custom Instructions are working. If something feels off — too long, wrong tone, generic — that's data. Update the instructions.
Custom Instructions evolve.
Yours won't be perfect on day one. They'll get better as you notice patterns — "Cowork keeps doing X and I want it to do Y," "Cowork keeps explaining things I don't need explained." Every time you notice a pattern, tell Cowork to update the rule. Within a few weeks, Family Manager genuinely behaves the way you want.
Next: Family Manager actually doing something useful.
One more lesson to close out Phase 2 — your first real use. We give Family Manager its first weekly meal plan and see what the system feels like when it's working.
Continue to Your First Real Use →