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.
npx agentmods add skills/drvoss/everything-copilot-cli/doubt-driven-developmentnpx skills add drvoss/everything-copilot-cli --skill doubt-driven-developmentgit clone --depth 1 https://github.com/drvoss/everything-copilot-cliWrote 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.
[](https://agentmods.dev/skills/drvoss/everything-copilot-cli/doubt-driven-development)<a href="https://agentmods.dev/skills/drvoss/everything-copilot-cli/doubt-driven-development"><img src="https://agentmods.dev/badge/skills/drvoss/everything-copilot-cli/doubt-driven-development.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00045 | $0.01111 |
| Opus 5 | $0.00023 | $0.00556 |
| Sonnet 5 | $0.00009 | $0.00222 |
| Haiku 4.5 | $0.00005 | $0.00111 |
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 today.
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.
How it starts
The opening of the file, as written. The whole thing — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Doubt-Driven Development
Doubt-Driven Development is an in-flight challenge loop for non-trivial decisions.
It is not a final code review and not a broad debate between many paths. It is a targeted attempt to disprove the current decision while the cost of changing course is still low.
When to Use
Apply this skill when the decision:
- changes branching logic or invariants
- crosses a module or service boundary
- asserts a property the compiler will not prove for you
- has irreversible or expensive blast radius
- depends on context that a future reader will not automatically see
Examples:
- "this caching layer is safe under concurrency"
- "this migration is reversible enough"
- "this module boundary is the right one"
When NOT to Use
| Instead of doubt-driven-development | Use |
|---|---|
| Choosing among several credible strategies | council |
| Getting a general second opinion before or after implementation | outside-voice |
| Proving a task is done with fresh command output | verification-before-completion |
| Mechanical edits like renames, formatting, or file moves | do the task |
Workflow
1. CLAIM - state what is standing
Write the current claim in one or two lines, plus why it matters.
Example:
Claim: the new retry logic is idempotent under duplicate delivery.
Why it matters: if this is wrong, users can be double-charged.
If you cannot state the claim clearly, you do not have a reviewable decision yet.
2. EXTRACT - isolate the smallest reviewable unit
Prepare only:
- the artifact under review
- the contract it must satisfy
Do not include your whole reasoning trail. Handing the reviewer your conclusion biases the result.
3. DOUBT - run an adversarial review
Use a fresh context if possible:
- another agent
- another model
- another reviewer pass with only artifact plus contract
Frame the prompt adversarially:
Find what is wrong with this artifact.
Assume the author is overconfident.
Look for hidden assumptions, broken contracts, edge cases, and failure modes.
Do not validate the decision. Surface issues.
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.
- today First seen · 153 lines · 45 tokens per session scan A 34ed132a0383
doubt-driven-development is a skill published in the GitHub repository drvoss/everything-copilot-cli (45 stars, last pushed 8d ago), licensed MIT. It adds 45 tokens to every session and 1,111 once invoked, about $0.0002 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 2026-09-03.
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