debugging-methodology

debugging-methodology is a skill for Claude Code, Codex from DevelopersGlobal/ai-agent-skills. It costs 26 tokens per session (942 once invoked), scanned A, original, MIT.

A structured way to find the underlying cause of software bugs by reproducing them, forming explanations, testing them, and then applying a fix.

In plain words
What is it for?
Use it for failing tests, errors, unexpected behavior between environments, and unexplained performance slowdowns.
Why use it?
It prevents random code changes that only hide symptoms or create new problems.

Skill for Claude CodeCodex

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

Good fit Use it for failing tests, errors, unexpected behavior between environments, and unexplained performance slowdowns.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/developersglobal/ai-agent-skills/debugging-methodology
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 DevelopersGlobal/ai-agent-skills --skill debugging-methodology
Clone the repo
git clone --depth 1 https://github.com/DevelopersGlobal/ai-agent-skills

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-methodology

README.md
[![agentmods](https://agentmods.dev/badge/skills/developersglobal/ai-agent-skills/debugging-methodology/github.svg)](https://agentmods.dev/skills/developersglobal/ai-agent-skills/debugging-methodology)
Your own site
<a href="https://agentmods.dev/skills/developersglobal/ai-agent-skills/debugging-methodology"><img src="https://agentmods.dev/badge/skills/developersglobal/ai-agent-skills/debugging-methodology/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-methodology

Your own site · 80×15
<a href="https://agentmods.dev/skills/developersglobal/ai-agent-skills/debugging-methodology"><img src="https://agentmods.dev/badge/skills/developersglobal/ai-agent-skills/debugging-methodology.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 26 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 942 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 $0.00026 $0.00942
Opus 5.5 $0.00010 $0.00377
Sonnet 5.5 $0.00005 $0.00188
Haiku 4.5 $0.00003 $0.00094

Measured 1mo ago against content hash 1e001991f84c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

debugging-methodology 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 1mo ago.

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-methodology/SKILL.md · 102 lines

How it starts

The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Overview

Random code changes in response to errors are not debugging — they're noise generation. This skill enforces a systematic, hypothesis-driven approach: understand the problem, form a hypothesis, test it, confirm the root cause, then fix.

AI agents often cycle through random fixes until something "works." This skill prevents that.

When to Use

  • Any time a test fails unexpectedly
  • Any time you encounter an error or exception
  • When behavior differs between environments
  • When performance degrades unexpectedly

Process

Step 1: Reproduce Reliably

  1. Before doing anything else: reproduce the bug reliably. If you can't reproduce it, you can't fix it.
  2. Write a failing test that captures the bug — this becomes your regression test.
  3. Note the exact conditions that trigger the bug: inputs, environment, sequence of actions.

Verify: You can trigger the bug on demand.

Step 2: Understand Before Diagnosing

  1. Read the full error message — not just the first line.
  2. Read the stack trace from bottom to top — the root cause is usually near the bottom.
  3. Identify: What was the program trying to do? What happened instead?

Verify: You can explain the bug in one sentence without using the word "error."

Step 3: Form a Hypothesis

  1. Based on what you know, form a specific hypothesis: "I think the bug is X because Y."
  2. The hypothesis must be falsifiable — you can design a test that proves or disproves it.
  3. Do not start making code changes until you have a hypothesis.

Verify: Your hypothesis is specific enough to design a test for.

Step 4: Test the Hypothesis

  1. Add targeted logging or a targeted test that confirms or refutes the hypothesis.
  2. Run it. Read the output carefully.
  3. If the hypothesis is wrong: update your understanding, form a new hypothesis, repeat.
  4. If the hypothesis is right: you've found the root cause.

Verify: Root cause is confirmed by evidence, not assumed.

Step 5: Fix the Root Cause (Not the Symptom)

Read the full file on GitHub · 102 lines

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. 1mo ago First seen · 102 lines · 26 tokens per session scan A 1e001991f84c

Subscribe to this mod's changes

debugging-methodology is a skill published in the GitHub repository DevelopersGlobal/ai-agent-skills (177 stars, last pushed 5mo ago), licensed MIT. It adds 26 tokens to every session and 942 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-08-30.

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