# Negation and Negative Instructions

> ones. "Don't use bullet points" may still produce bullets. Complex negations ("never fail to include") can be misinterpreted.

- Skill: `tools-only/negation-and-negative-instructions` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add tools-only/negation-and-negative-instructions`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tools-only/negation-and-negative-instructions/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tools-only (https://skillmd.com/u/tools-only)
- Updated: 2026-09-29
- Page: https://skillmd.com/skills/tools-only/negation-and-negative-instructions

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# Negation and Negative Instructions

**Opus**: Processes negative instructions ("don't include X") reliably.
Understands complex negations and double negatives.

**Haiku**: Negative instructions are less reliably followed than positive
ones. "Don't use bullet points" may still produce bullets. Complex
negations ("never fail to include") can be misinterpreted.

**Mitigation**: Reframe every negative as a positive directive.

```
BAD:  Don't use jargon.
GOOD: Use plain language that a high school student would understand.

BAD:  Never include personal opinions.
GOOD: State only facts supported by the provided data.

BAD:  Don't forget to include the date.
GOOD: Include the date in YYYY-MM-DD format on the first line.
```

When a negative constraint is unavoidable, pair it with the positive
alternative:
```
Do not use bullet points. Instead, write in flowing prose paragraphs.
```

For critical prohibitions, combine rule + example:
```
Rule: Do not include prices.
Example output shows: "Contact sales for pricing." (not "$99/month")
```