Claude Prompting Tips: Simplify for Better Fable Performance
Summary
New insights suggest that Claude, particularly Fable, performs better with simpler prompts, avoiding excessive examples or negative constraints. Claude Code's system prompt was recently reduced by 80%, indicating a shift towards more concise instructions.
Why it matters
Professionals can improve the efficiency and accuracy of their AI interactions by adopting more streamlined prompting techniques, potentially reducing token usage and improving model output quality.
How to implement this in your domain
- 1Review existing Claude prompts for unnecessary examples or negative constraints.
- 2Experiment with simplifying prompts by removing redundant information.
- 3Test the performance of concise prompts against verbose ones for specific tasks.
- 4Train teams on the principle of "less is more" when crafting AI instructions.
Who benefits
Key takeaways
- Overloading Claude prompts with examples or negative lists can hinder performance.
- Simpler, more concise prompts often lead to better results with Claude and Fable.
- Claude Code's internal system prompt was significantly reduced, validating this approach.
- Optimizing prompt length can improve AI efficiency and output quality.
Original post by @simonw
"I got some really useful Claude prompting tips from @_catwu and @trq212 - it's time to stop overloading our prompts with examples and lists of things not to do, Fable works better without those Claude Code's own system prompt recently shrunk by 80%! Here's my full write-up of our…"
View on X
Originally posted by @simonw on X · view source
Want to go deeper?
Turn these trends into skills with Learnijoy's hands-on AI & tech courses.
Explore coursesMore in AI Engineering & DevTools

Google Releases New Gemini Flash Models, Benchmarks Lower Than Rivals
Google has launched Gemini 3.6 Flash and Gemini 3.5 Flash Lite, focusing on efficiency and price improvements over previous versions. While these models offer upgrades, their benchmarks generally fall below mid-tier competitors like Grok 4.5 and GPT-5.6 Luna.
Amazon Nova Explores Self-Distilled Reasoning for Fine-Tuning
Amazon Nova researchers are investigating Self-Distilled Reasoning (SDR) to generate 'thinking tokens' for datasets lacking explicit reasoning traces in supervised fine-tuning. This technique aims to address the reasoning suppression problem and has been validated across three benchmarks, with practical recommendations provided.
Profluent's ProGen Model Achieved Breakthrough in Protein Design
Profluent's initial 1.2 billion-parameter ProGen model, once the largest in physical sciences, successfully generated novel proteins with exceptionally high hit rates. These de novo proteins demonstrated functionality comparable to those evolved over millions of years, marking a significant advancement in the field.