Debugging

Debugging is a skill for Claude Code, Codex from hainamchung/agent-assistant. It costs 67 tokens per session (705 once invoked), scanned A, original, MIT.

A structured method for finding the underlying cause of bugs, failed tests, performance problems, and other unexpected behavior before changing code.

In plain words
What is it for?
It helps investigate failures, compare working and broken cases, test possible explanations, and verify that a fix actually works.
Why use it?
It reduces guesswork and prevents quick fixes that hide the real problem or create new bugs.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit It helps investigate failures, compare working and broken cases, test possible explanations, and verify that a fix actually works.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hainamchung/agent-assistant/debugging
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add hainamchung/agent-assistant --skill debugging
Clone the repo
git clone --depth 1 https://github.com/hainamchung/agent-assistant

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for Debugging

README.md
[![agentmods](https://agentmods.dev/badge/skills/hainamchung/agent-assistant/debugging/github.svg)](https://agentmods.dev/skills/hainamchung/agent-assistant/debugging)
Your own site
<a href="https://agentmods.dev/skills/hainamchung/agent-assistant/debugging"><img src="https://agentmods.dev/badge/skills/hainamchung/agent-assistant/debugging/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for Debugging

Your own site · 80×15
<a href="https://agentmods.dev/skills/hainamchung/agent-assistant/debugging"><img src="https://agentmods.dev/badge/skills/hainamchung/agent-assistant/debugging.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 67 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 705 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00067 $0.00705
Opus 5 $0.00034 $0.00352
Sonnet 5 $0.00013 $0.00141
Haiku 4.5 $0.00007 $0.00071

Measured 8d ago against content hash 43639a9454cd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

Debugging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/find-polluter.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/debugging/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Debugging

Comprehensive debugging framework combining systematic investigation, root cause tracing, defense-in-depth validation, and verification protocols.

Core Principle

NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST

Random fixes waste time and create new bugs. Find the root cause, fix at source, validate at every layer, verify before claiming success.

When to Use

Always use for: Test failures, bugs, unexpected behavior, performance issues, build failures, integration problems, before claiming work complete

Especially when: Under time pressure, "quick fix" seems obvious, tried multiple fixes, don't fully understand issue, about to claim success

The Four Techniques

1. Systematic Debugging (references/systematic-debugging.md)

Four-phase framework ensuring proper investigation:

  • Phase 1: Root Cause Investigation (read errors, reproduce, check changes, gather evidence)
  • Phase 2: Pattern Analysis (find working examples, compare, identify differences)
  • Phase 3: Hypothesis and Testing (form theory, test minimally, verify)
  • Phase 4: Implementation (create test, fix once, verify)

Key rule: Complete each phase before proceeding. No fixes without Phase 1.

Load when: Any bug/issue requiring investigation and fix

2. Root Cause Tracing (references/root-cause-tracing.md)

Trace bugs backward through call stack to find original trigger.

Technique: When error appears deep in execution, trace backward level-by-level until finding source where invalid data originated. Fix at source, not at symptom.

Includes: scripts/find-polluter.sh for bisecting test pollution

Load when: Error deep in call stack, unclear where invalid data originated

3. Defense-in-Depth (references/defense-in-depth.md)

Validate at every layer data passes through. Make bugs impossible.

Four layers: Entry validation → Business logic → Environment guards → Debug instrumentation

Load when: After finding root cause, need to add comprehensive validation

Read the full file on GitHub · 85 lines

Files

What ships with it

6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 85 lines · 67 tokens per session scan A 43639a9454cd

Subscribe to this mod's changes

Debugging is a skill published in the GitHub repository hainamchung/agent-assistant (54 stars, last pushed 3mo ago), licensed MIT. It adds 67 tokens to every session and 705 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.