# Diagnose

> >-

- **Type:** Skill
- **Install:** `agentstack add skill-adit-jain-srm-skill-forge-diagnose`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [Adit-Jain-srm](https://agentstack.voostack.com/s/adit-jain-srm)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [Adit-Jain-srm](https://github.com/Adit-Jain-srm)
- **Source:** https://github.com/Adit-Jain-srm/skill-forge/tree/main/skills/diagnose
- **Website:** https://github.com/Adit-Jain-srm/skill-forge#quick-start

## Install

```sh
agentstack add skill-adit-jain-srm-skill-forge-diagnose
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

## Overview

Systematic debugging that produces evidence at every step — not guesswork, not shotgun fixes.

## Process

Do NOT guess. Follow the loop. Every step produces evidence.

## The Loop

```
1. REPRODUCE — make it fail on demand. If you can't reproduce, you can't fix.
2. MINIMISE — strip everything until only the bug remains. Smallest failing case.
3. HYPOTHESISE — ONE theory. Not three. One. State it clearly.
4. INSTRUMENT — add the ONE measurement that proves/disproves your hypothesis.
5. EVALUATE — run it. Was hypothesis correct?
   YES → go to step 6
   NO  → back to step 3 with new information
6. FIX — minimal change that addresses root cause (not symptoms)
7. REGRESSION TEST — write a test that would have caught this. Run it red then green.
```

## Rules

- Never skip REPRODUCE. "I think it fails when..." is not reproducing.
- Never fix without a hypothesis. Shotgun debugging = wasted time.
- One hypothesis at a time. Changing two things = you learn nothing.
- The fix must address ROOT CAUSE. If you're fixing symptoms, you're not done.
- The regression test must FAIL without the fix applied.

## Anti-Patterns (stop yourself)

- "Let me try adding a null check here" → NO. Where's your hypothesis? What evidence?
- "It's probably a timing issue" → Probably? REPRODUCE it. PROVE it's timing.
- "I'll add some console.logs" → WHICH log proves WHICH hypothesis? Be specific.
- "Fixed! (without running the test)" → NO. Prove it. Run it. Evidence.

## Common Mistakes

- Changing two things at once — you learn nothing about which fixed it
- "Probably" without evidence — reproduce it or it's speculation
- Fixing symptoms (adding null checks) instead of root causes (why was it null?)
- Declaring "fixed" without a regression test proving it

## Example

```
Bug: "Login button sometimes doesn't respond"

1. REPRODUCE: Click login 20 times → fails on attempts 7, 14, 19 (pattern?)
2. MINIMISE: Remove all other UI. Just the button + handler. Still fails.
3. HYPOTHESISE: "Event listener is being attached multiple times on re-render"
4. INSTRUMENT: Add counter in useEffect → logs show 3 listeners after 3 renders
5. EVALUATE: Hypothesis confirmed. Missing cleanup in useEffect.
6. FIX: Add return () => btn.removeEventListener(...) in useEffect
7. REGRESSION TEST: test('login handler attaches exactly once after re-renders')
```

## Persistence

ACTIVE whenever debugging. Stay in the loop until the regression test is green. Don't exit early. Don't declare "fixed" without step 7.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [Adit-Jain-srm](https://github.com/Adit-Jain-srm)
- **Source:** [Adit-Jain-srm/skill-forge](https://github.com/Adit-Jain-srm/skill-forge)
- **License:** MIT
- **Homepage:** https://github.com/Adit-Jain-srm/skill-forge#quick-start

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-adit-jain-srm-skill-forge-diagnose
- Seller: https://agentstack.voostack.com/s/adit-jain-srm
- Browse the marketplace: https://agentstack.voostack.com/browse

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Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.