fable-task-brief.txt
I'm working on <the larger goal> for <who it's for>. They need <what
the output enables>.

With that in mind, build: <the complete task>

Constraints: <stack, files that must not change, style rules>
Done means: <specific, checkable conditions>
Verify by: <the test command, or how to check it works>

Do the whole thing. Don't stop to ask about decisions covered here.

Fable 5.1 does better when it understands why. The first two lines aren't padding — they change how it connects the task to your codebase.