resume-claim-guard is an open-source MIT-licensed AI agent skill and workflow guard for tailoring a resume to a job description without inventing anything. Instead of letting a language model fabricate metrics or inflate project ownership, it first interviews the candidate with a few questions, builds a verified fact list, and only then tailors the resume to the posting, keeping roles, stages, and numbers honest. The repository includes a skill definition, a prompt file, templates, and a validation script, and it runs inside the user own ChatGPT, Claude, Kimi, DeepSeek, or Claude Code session, so any model cost is the user own. It is free, and as a single skill file rather than a hosted tool, it does nothing without the user language model. It is aimed at job seekers and the product managers and engineers who review their own resumes, and its value is restraint: in a market where AI-polished resumes are easy to spot and easy to distrust, a guard that keeps every claim checkable is the feature.