Rewrite your AI prompts using the Claude Fable 5.2 system prompt as a template - in 10 minutes

This is Anthropic's official document, updated November 9, 2026. A 426-thousand-character file circulating on social media from an anonymous account is unverified - do not use it as a source: 94% of its text cannot be cross-checked.

According to Anthropic's tests, with this text roughly half as many agent sessions end with unfinished work. The guide is fully open and free.

All listed services have a free tier and do not require a card. If one is unavailable in your region - just pick another from the list.

Do not paste personal or confidential data into the prompt: the text goes to a third-party server. Your current prompt is what you normally write to an AI - for example, «write me an email to a client».

Below is the official system prompt of Claude Fable 5.2, published by Anthropic. Study how it is structured: explicit role definition, clear scope boundaries, formatting rules, tone instructions, and handling of edge cases.

--- SYSTEM PROMPT ---
[PASTE THE PROMPT TEXT FROM THE ANTHROPIC DOCS PAGE HERE]
--- END SYSTEM PROMPT ---

Now apply the same techniques to improve MY prompt.

My task: [YOUR TASK IN ONE SENTENCE]
My current prompt: [YOUR CURRENT PROMPT HERE]

Rewrite my prompt so it: 1) defines an explicit role for the model, 2) states scope and boundaries, 3) specifies output format and length, 4) includes a rule to persist and finish the work without stopping to ask unnecessary questions. Output ONLY the improved prompt, ready to copy-paste. After it, add 3 short bullet points explaining what you changed and why.

The key phrase from this block: «Please avoid stopping while you still owe work the user asked for. Be persistent and do not stop unless needed» - the model should work around errors and timeouts on its own, without asking permission for every step. But keep confirmation for genuinely dangerous actions.

Usually one or two iterations are enough. If the service is unavailable in your region, the entire recipe works in any other chatbot from the step 3 list - the techniques from the system prompt are universal.