A confident answer is not a correct one. Long sessions accumulate context that quietly turns assumptions into "facts" without anyone noticing. Doubt-driven development is the discipline of materializing a fresh-context reviewer — biased to disprove, not approve — before any non-trivial output stands.
Doubt Driven Development is a community-contributed Claude Code skill in the security-misc sub-category. It ships as a SKILL.md file that Claude Code auto-discovers under ~/.claude/skills/doubt-driven-development/ and loads when your prompt matches the skill's trigger.
When to invoke it: Use when correctness matters more than speed, when working in unfamiliar code, when stakes are high (production, security-sensitive logic, irreversible operations), or any time a confident output would be cheaper to verify now than to debug later. Don't use for mechanical operations (renames, formatting), one-line changes with obvious correctness, or when the user has explicitly asked for speed over verification.
The Doubt Driven Development Claude Code skill is built for security engineers, penetration testers, DevSecOps practitioners, and development teams hardening codebases and infrastructure. It's part of ClaudSkills (also referred to as Claude Skills or Claude Code Skills) — the open community-curated registry of 69,000+ SKILL.md files for Anthropic's Claude Code agent and the wider Claude ecosystem (Claude API, Claude Agent SDK).
mkdir -p ~/.claude/skills/doubt-driven-development curl -L https://claudskills.com/skills/doubt-driven-development/SKILL.md \ -o ~/.claude/skills/doubt-driven-development/SKILL.md
Or just download SKILL.md directly and drop it into ~/.claude/skills/doubt-driven-development/. Claude Code auto-discovers it on next session.
Skills live at ~/.claude/skills/doubt-driven-development/SKILL.md on macOS/Linux, or %USERPROFILE%\.claude\skills\doubt-driven-development\SKILL.md on Windows. See the full install guide for step-by-step instructions.
The ClaudSkills desktop app installs any skill directly into ~/.claude/skills/ with one click — no terminal required. Pro starts at $9/mo or $149 lifetime.
For the full experience including quality scoring and one-click install features for each skill — upgrade to Pro.
Browse all Security skills in the ClaudSkills registry, or explore these other picks from the same category:
Part of Acreator Store — Adam Lankamer's AI tools: PerfectStudio · Ucaption · UTagger · AutoXPoster · TestYourSkills · AutomationFlows · Au Naturel
SKILL.md files, not affiliated with, endorsed by, or sponsored by Anthropic.