A single misplaced disallow rule in robots.txt can quietly block a search engine from crawling pages, or even entire sections, that you actually want indexed.
Don't Block Resources You Need Rendered
CSS and JavaScript files blocked by robots.txt can prevent search engines from rendering your page correctly, which was a common mistake on older CMS defaults.
Be Specific With Disallow Rules
Overly broad rules meant to block one folder can accidentally catch unrelated pages that share part of the same URL path.
Test Before You Deploy
Always verify a new robots.txt against your actual URL patterns before pushing it live, since the cost of a mistake is invisibility, not a warning.
Next step: Use the Robots.txt Generator to build and double-check your rules before publishing them.