"CLAUDE.md files solve this by giving Claude persistent context about your project. A well-configured CLAUDE.md transforms how Claude works with your specific project. The file serves multiple purposes: providing architectural context, establishing workflows, and connecting Claude to your development tools. Each addition should solve a real problem you have encountered, not theoretical concerns about what Claude might need."
I pretty clearly say I still use CLAUDE.md/AGENTS.md
I've just been trimming down to the recommended < 100 lines and I keep only super high level info in there and allow the agents to figure things out by reading the code.
I wouldn't use a blog post from Nov 2025 be my guiding light.
Anthropic over the past few months have said they've cut their system prompts 80%. These are current best practices. The models are good enough and can figure things out on their own BETTER than you can present the info in markdown files and "decision" documents.
While arguing against using the tool as designed.
https://claude.com/blog/using-claude-md-files
"CLAUDE.md files solve this by giving Claude persistent context about your project. A well-configured CLAUDE.md transforms how Claude works with your specific project. The file serves multiple purposes: providing architectural context, establishing workflows, and connecting Claude to your development tools. Each addition should solve a real problem you have encountered, not theoretical concerns about what Claude might need."