de-prescribe.txt
Here's a prompt I've been using with older models: <paste>

Rewrite it for Claude Fable 5.1. Keep: the goal, constraints, definition
of done, how to verify, and communication preferences. Remove:
step-by-step instructions for how to do the task, reasoning
instructions ("think carefully", "consider edge cases"), and rules
guarding against behaviours an older model had.

Show me what you cut and why. Then the shorter version.

Then run both on a real task and compare. Prompts written for prior models are often too prescriptive for Fable 5.1 and reduce what comes back.