Cursor Rules: How to Stop Your AI Agent From Writing Slop
You just installed Cursor, opened a TypeScript file, and asked the agent to fix a bug. Ten seconds later it handed you a type SomeType = any and a @ts-ignore above the line that wouldn't compile. This is the moment most developers discover that AI coding agents are powerful but undisciplined. The fix isn't a better model. It's rules. Most AI coding agent best practices boil down to a single idea:…
Cursor rules are markdown files that provide instructions to AI agents before they start working on code. These files, stored in .cursor/rules/ at the project root, have a YAML frontmatter block and a markdown body containing the instructions. The three essential frontmatter fields are description, globs (optional), and alwaysApply (optional).
To configure cursor rules effectively, it's crucial to specify clear requirements, include anti-patterns to avoid, and use globs to scope rules to specific file types. Common mistakes include vague rules, lack of anti-patterns, absence of globs, and not verifying that the agent followed the rules. To improve the effectiveness of cursor rules, use a few sharp rules instead of many vague ones, and consider using AGENTS.md for repository-wide information.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — it may contain errors, so check the original before relying on it.
