doubt-driven-development

doubt-driven-development is a skill for Claude Code, Codex from vignesh2027/AI-AGENT-SKILLS. It costs 14 tokens per session (300 once invoked), scanned A, original, MIT.

A review method for finding assumptions and hidden dependencies in requirements, code, and integrations before they cause bugs. It makes important assumptions explicit and asks for evidence or tests.

In plain words
What is it for?
Use it to list assumptions, judge their risks, verify important ones with tests, documentation, measurements, or expert input, and record what remains unverified.
Why use it?
It reduces failures caused by treating unverified behavior as certain, especially when relying on external systems or unclear requirements.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to list assumptions, judge their risks, verify important ones with tests, documentation, measurements, or expert input, and record what remains unverified.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/vignesh2027/ai-agent-skills/doubt-driven-development
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add vignesh2027/AI-AGENT-SKILLS --skill doubt-driven-development
Clone the repo
git clone --depth 1 https://github.com/vignesh2027/AI-AGENT-SKILLS

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for doubt-driven-development

README.md
[![agentmods](https://agentmods.dev/badge/skills/vignesh2027/ai-agent-skills/doubt-driven-development.svg)](https://agentmods.dev/skills/vignesh2027/ai-agent-skills/doubt-driven-development)
Your own site
<a href="https://agentmods.dev/skills/vignesh2027/ai-agent-skills/doubt-driven-development"><img src="https://agentmods.dev/badge/skills/vignesh2027/ai-agent-skills/doubt-driven-development.svg" alt="Measured on agentmods" height="20"></a>
Per session 14 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 300 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00014 $0.00300
Opus 5 $0.00007 $0.00150
Sonnet 5 $0.00003 $0.00060
Haiku 4.5 $0.00001 $0.00030

Measured 8d ago against content hash db90ca9fdbce, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

doubt-driven-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/doubt-driven-development/SKILL.md · 42 lines

What it actually says

Overview

Every "I'm sure this is fine" is a future incident. This skill applies systematic skepticism to assumptions in requirements, implementations, and integrations before they ship.

When to Use

  • When something "seems obvious" but hasn't been verified
  • When implementing code that depends on external behavior
  • When code review reveals an implicit assumption
  • When debugging a "that's impossible" bug

Process

Step 1: List your assumptions

For every non-trivial implementation, write down all the things that must be true for it to work. Make implicit assumptions explicit.

Step 2: Classify by risk

For each assumption: what is the cost if it's wrong? High-cost assumptions must be verified before shipping.

Step 3: Verify high-cost assumptions

How to verify:

  • Write a test that fails if the assumption is wrong
  • Find the source of truth (spec, documentation)
  • Measure it (add a log, run a query)
  • Ask someone who knows

Step 4: Make remaining assumptions visible

For assumptions you can't verify before shipping: document them as known assumptions. Future engineers must be able to find them.

Verification Requirements

  • All non-trivial assumptions listed
  • High-cost assumptions verified before shipping
  • Remaining assumptions documented in code
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 42 lines · 14 tokens per session scan A db90ca9fdbce

Subscribe to this mod's changes

doubt-driven-development is a skill published in the GitHub repository vignesh2027/AI-AGENT-SKILLS (2 stars, last pushed 10d ago), licensed MIT. It adds 14 tokens to every session and 300 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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