# Tell your AI to flag ambiguous data, not silently guess what it means

Published: 2026-06-02T00:00:00.000Z
Canonical: https://wow.pjh.is/journal/flag-ambiguous-data

I recently added the following to my `AGENTS.md` file:

**Prompt**

```

## Ambiguous evidence in high-stakes decisions

When using screenshots, OCR, copied tables, charts, dashboards, forms, PDFs, or other visual data, do not guess unclear headings, labels, units, signs, dates, currencies, or context.

For high-stakes decisions—especially finance, tax, legal, medical, security, irreversible account actions, large purchases, or anything plausibly over $1,000—first extract the key facts into a structured, user-verifiable table, marking visible versus inferred fields. If any ambiguous, inferred, or unverified field could change the recommendation, stop and ask for clearer evidence or confirmation.

Prefer CSVs, exported reports, transaction logs, broker statements, or copy-pasted tables with headings over screenshots. Screenshots should not be treated as reliable structured data unless labels and values are clearly visible.

```

Motivation: last week I nearly made a >$10K mistake while working with AI.

I was doing a personal finance review. A high-stakes question came up: whether to sell or hold a large ITM options position. I pasted screenshots of the position details, consulted Claude, then used [ask many models](https://wow.pjh.is/journal/ask-many-models) to get a second opinion from GPT-5.5 Pro, Gemini Pro and Grok. All of them agreed on the bottom line, with high confidence.

But the bottom line surprised me. So I asked Claude to triple-check everything—and specifically to re-examine the position details we'd sent via ask many models. Claude noticed my screenshots didn't include column headings, and that it wasn't entirely sure about the meanings of some of the columns. I pasted in unambiguous screenshots, and Claude confirmed that it had misread the columns. Correcting the numbers flipped the conclusion (for Claude, and all other models).

I could easily have skipped this triple-check and gone ahead with the trade. That would have been a >$10K mistake.

The two heuristics that saved me:

* For high-stakes decisions, triple-check, and be sure to think for yourself.
* If a model output is surprising, be skeptical.

This illustrates a broader failure mode: "model makes a confident, incorrect assumption and doesn't flag it". I [often run into this problem](https://wow.pjh.is/journal/incorrect-assumptions) when trying ambitious delegation of non-coding tasks.