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 skills add alivirgo/Major-AI-Skills --skill double-check-ai-math-manuallygit clone --depth 1 https://github.com/alivirgo/Major-AI-SkillsWrote 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/alivirgo/major-ai-skills/double-check-ai-math-manually)<a href="https://agentmods.dev/skills/alivirgo/major-ai-skills/double-check-ai-math-manually"><img src="https://agentmods.dev/badge/skills/alivirgo/major-ai-skills/double-check-ai-math-manually/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/alivirgo/major-ai-skills/double-check-ai-math-manually"><img src="https://agentmods.dev/badge/skills/alivirgo/major-ai-skills/double-check-ai-math-manually.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00027 | $0.01120 |
| Opus 5 | $0.00014 | $0.00560 |
| Sonnet 5 | $0.00005 | $0.00224 |
| Haiku 4.5 | $0.00003 | $0.00112 |
Grade A, and why
double-check-ai-math-manually 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 — 113 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Double-Check AI Math Manually (Deterministic Verification) (AI Skill)
Overview
Because Large Language Models are probabilistic language generators rather than algebraic engines, they can generate an impeccable financial breakdown where the individual line items look flawless, but the sum at the bottom is subtly wrong by $150 or 2.5%.
The 3-Tier Math Verification Ladder provides a safety net to ensure that no AI-generated financial quote, invoice, equity cap table, or budget is delivered without deterministic proof of accuracy.
The 3-Tier Math Verification Ladder
┌─────────────────────────────────────────────────────────────┐
│ 3-Tier Math Safety Ladder │
│ │
│ [ TIER 1: AI Formula Derivation ] │
│ • Define variables, logic, and standard formulas │
│ │ │
│ ▼ │
│ [ TIER 2: Code / Python Execution ] │
│ • Force the AI to execute Python math programmatically │
│ │ │
│ ▼ │
│ [ TIER 3: Deterministic Human Check ] │
│ • Paste values into Excel, Google Sheets, or a calculator │
│ • 100% Guaranteed Mathematical Integrity │
└─────────────────────────────────────────────────────────────┘
High-Risk Math Scenarios Requiring Tier-3 Verification
- Client Invoices & Estimates: Multi-line hourly rates with discounts and tax percentages.
- Cap Tables & Equity Dilution: Post-money SAFE notes, option pools, and vesting calculations.
- Loan & Mortgage Amortization: Compound interest formulas ($M = P \frac{r(1+r)^n}{(1+r)^n - 1}$).
- Tax Withholdings & Deductions: Progressive bracket brackets and FICA thresholds.
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 Changed · -11 tokens per session f52e7224d7b5
- 12d ago First seen · 113 lines · 38 tokens per session scan A ef02231da972
double-check-ai-math-manually is a skill published in the GitHub repository alivirgo/Major-AI-Skills (1 stars, last pushed today), licensed MIT. It adds 27 tokens to every session and 1,120 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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