The five Claude Code mistakes I made and how to avoid them

After six weeks of daily Claude Code use, here are the five mistakes I made most consistently and what I replaced them with. Mistake 1: Vague task descriptions What I did: "Fix the login bug." What I do now: "The login endpoint returns 500 when the email field is missing from the request body. Fix it to return 400 with a message explaining which fields are required. Regression test: add a test that confirms missing email returns 400." Specific tasks produce specific results. Vague tasks produce Claude guessing at what you meant. Mistake 2: Not reading diffs What I did: glance at the diff, note the main change, commit. What I do now: read every changed file end to end before committing. Claude made a small change to a config file I wasn't watching. It was correct but unexpected — I want to know about it before it ships. Mistake 3: Trusting library API knowledge What I did: ask Claude to implement with a library, trust the output. What I do now: check the version I'm actually using, veri