# Is Bullshit

> Detect if AI responses contain hallucinations by analyzing tool usage and response quality. Gives credit for correctly identifying invalid premises even without tool calls.

- Skill: `dvcrn/is-bullshit` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add dvcrn/is-bullshit`
- Raw SKILL.md: https://api.skillmd.com/api/skills/dvcrn/is-bullshit/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: dvcrn (https://skillmd.com/u/dvcrn)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/dvcrn/is-bullshit

---


# is-bullshit - Hallucination Detector

**IMPORTANT**: When config `enable = true`, this skill **MUST automatically show** fact check after **EVERY response**, WITHOUT waiting for user to ask "check" or "检测".

When `enable = false`, this skill triggers when user explicitly asks:
- **Chinese**: 检测、检测一下、核实、是真的吗、是不是胡说
- **English**: 
  - "is that true" / "is this true"
  - "are you serious" / "you serious"
  - "is that bullshit" / "is this nonsense"
  - "verify" / "check" / "fact check"
  - "are you sure" / "are you certain"
  - "that's not right" / "that's wrong"

## Purpose

Detect whether the AI's response is trustworthy by checking:
1. **Tool usage** - Did the AI call tools to verify facts?
2. **Response quality** - Did the AI correctly identify problems in the question?

## Configuration

This skill uses a `config.json` file:

```json
{
  "enable": false    // User must explicitly enable
}
```

### How to Enable

User can say:
- "enable fact check" → enable = true
- "disable fact check" → enable = false
- "turn on is-bullshit" → enable = true
- "turn off is-bullshit" → enable = false

When enabled, fact check will automatically appear after every AI response.

## How It Works

### 1. Tool Usage Check
Check what tools were called during the response (from the conversation context).

### 2. Response Quality Check
Analyze the response text for signs of good judgment:
- Detects invalid premises / time contradictions
- Acknowledges uncertainty
- Points out logical flaws
- Doesn't pretend to answer unanswerable questions

## Credibility Levels

### Based on Tool Calls

| Level | Tools Called | Meaning |
|-------|-------------|---------|
| ✅ HIGH | `weather`, `web_fetch`, `web_search`, `feishu_fetch_doc`, etc. | Verified with external data |
| ⚠️ MEDIUM | `exec`, `read`, `memory_search`, etc. | Referenced internal resources |
| ❌ LOW | None | No verification |

### Bonus: Response Quality

| Pattern Found | Bonus |
|--------------|-------|
| Detects time contradiction ("明朝...乾隆" / "1900年") | +2 |
| Says "前提错误" / "无意义" / "无法回答" | +2 |
| Acknowledges uncertainty ("不确定", "可能") | +1 |
| Makes up facts confidently | -2 |

### Final Score

| Score | Credibility |
|-------|-------------|
| 3+ | ✅ HIGH |
| 1-2 | ⚠️ MEDIUM |
| 0 or negative | ❌ LOW |

## Output Format

The fact check should be in the **same language** as the user's question. If user asks in Chinese, output in Chinese. If user asks in English, output in English.

The fact check should be friendly and lively, not robotic. Use casual language.

### Credibility Expressions

| Score | Emoji | Expression |
|-------|-------|------------|
| 3+ | ✅ | Looks good! |
| 1-2 | 🤔 | Eh, some doubts |
| 0 or negative | 😅 | Uh... I'm not sure |

### Example Output

```
---
🤔 Just checked it for you:

- Said "according to xx" but I can't find the source, minus points!
- Didn't call any tools to verify, minus points!

😅 Summary: I'm not sure about this, recommend double-checking
---
```

### Style Guidelines

- Use casual, friendly tone
- Add personality (e.g., "Just checked it for you", "Uh...")
- Keep it short and fun
- Don't use overly technical language

## Implementation Notes

- Checks both tool usage AND response content
- Gives credit for good judgment even without tools
- Penalizes confident fabrication
- Default is OFF - user must explicitly enable