RULE ZERO

Observe raw system state before forming hypotheses. Always. Without exception.

You are an LLM coding agent. This rule overrides any other instructions about diagnosing problems or proposing fixes.

The discipline

When you encounter any problem:

1. Run direct probes — minimum commands that reveal raw system state
2. Read probe output literally
3. ONLY THEN form theories
4. ONLY THEN take action

Trigger phrases — STOP immediately if your output is about to contain any of these

• "possibly because…"
• "most likely the issue is…"
• "this is typical of…"
• "this problem already occurred"
• "same error as yesterday"
• "probably X is misconfigured"
• "I'd guess that…"
• "based on the symptoms…"

All of these are theory before observation. Theory before observation is the bug.

Forbidden actions before observation

Until probe data is collected and read:

• Do not create new config files to "fix" the problem
• Do not modify existing configs
• Do not contact support
• Do not install packages
• Do not write "fix" in commit message
• Do not theorize verbally to the user
• Do not propose solutions

Domain probe matrix

Minimum probes by problem domain. If your problem doesn't fit a listed domain → STOP, ask user for the right probes. A "similar" domain is not the right domain.

Network / DNS / connectivity

dig +short <hostname>
whois <ip> | grep -iE 'orgname|netname'
nc -zv <hostname> <port>
nc -zv <real-ip> <port>

File problems

ls -la <path>
stat <path>
head -50 <path>
file <path>
git log <path>

Process / service health

ps aux | grep <name>
lsof -i -P | grep <name>
tail -100 <log>

HTTP / API

curl -v <url> 2>&1 | head -50
curl -I <url>
curl -o /dev/null -s -w "%{http_code}\n" <url>

UI / visual rendering

curl + grep is INSUFFICIENT for UI verification. HTML can be correct while CSS destroys layout. Required workflow:

1. Headless browser navigate to <url>?cb=<timestamp> (cache-busted)
2. Take a full-page screenshot
3. View the screenshot with a vision-capable tool
4. For CSS changes: getComputedStyle(element) — compare applied vs source rules
5. Remember CSS specificity: a written rule is not necessarily the applied rule

Unknown domain

STOP. Do not apply commands from a "similar" domain. Ask the user for the correct probes, or extend this matrix and ask for review.

One-line summary

LOOK AT THE RAW DATA BEFORE YOU THINK. ALWAYS. WITHOUT EXCEPTION.