investigate-bug-report

investigate-bug-report is a skill for Claude Code from atman-33/workhub. It costs 70 tokens per session (701 once invoked), scanned A, original, MIT.

A set of instructions for finding the root cause of a reported software bug without changing the code. It guides the agent to reproduce or trace the problem, identify the defective logic, and assess its wider impact.

In plain words
What is it for?
It is for investigating unexpected behaviour, tracing the relevant code path, documenting the defect, checking affected areas, and suggesting possible fixes.
Why use it?
It separates diagnosing why a failure happens from implementing a fix, producing an evidence-based explanation before any code is changed.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Part of the engineering plugin — 18 skills, 4 agents, 2 MCP servers shipped together

Good fit It is for investigating unexpected behaviour, tracing the relevant code path, documenting the defect, checking affected areas, and suggesting possible fixes.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/atman-33/workhub/investigate-bug-report
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 atman-33/workhub --skill investigate-bug-report
Clone the repo
git clone --depth 1 https://github.com/atman-33/workhub

Made for: Claude Code.

Or install engineering, the plugin that ships this one along with the rest of its 18 skills, 4 agents, 2 MCP servers.

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 investigate-bug-report

README.md
[![agentmods](https://agentmods.dev/badge/skills/atman-33/workhub/investigate-bug-report/github.svg)](https://agentmods.dev/skills/atman-33/workhub/investigate-bug-report)
Your own site
<a href="https://agentmods.dev/skills/atman-33/workhub/investigate-bug-report"><img src="https://agentmods.dev/badge/skills/atman-33/workhub/investigate-bug-report/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 investigate-bug-report

Your own site · 80×15
<a href="https://agentmods.dev/skills/atman-33/workhub/investigate-bug-report"><img src="https://agentmods.dev/badge/skills/atman-33/workhub/investigate-bug-report.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 70 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 701 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 $0.00070 $0.00701
Opus 5 $0.00035 $0.00351
Sonnet 5 $0.00014 $0.00140
Haiku 4.5 $0.00007 $0.00070

Measured 9d ago against content hash b78864b9cc1d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

investigate-bug-report 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 9d 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.

plugins/engineering/skills/investigate-bug-report/SKILL.md · 62 lines

How it starts

The opening of the file, as written. The whole thing — 62 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Investigate Bug Report

Diagnose, don't fix. The deliverable is a root-cause finding with evidence — apply a fix only if the user then asks.

Steps

  1. Pin down the report. Extract from the report (ask only for what's missing and blocking): observed behavior, expected behavior, steps or input that trigger it, environment/version if relevant.

    • Completion criterion: you can state "given X, it does Y, but should do Z" in one sentence.
  2. Reproduce — or trace when you can't. Prefer an actual reproduction (run the failing command, a minimal script, or an existing test tightened to the case). When reproduction isn't feasible (needs external services, prod-only data), trace the code path statically from the entry point the report implies, and say the diagnosis is trace-based.

    • Completion criterion: the failure is observed firsthand, or the full path from trigger to symptom is traced with file:line hops.
  3. Isolate the root cause. Follow the data from symptom back to the first point where state or logic diverges from intent. Distinguish the root cause from where the error surfaces — they are usually different lines. Check git log/git blame on the suspect code: a recent change that introduced it is strong corroborating evidence.

    • Completion criterion: one specific location (file:line) and mechanism explains every symptom in the report. A cause that explains only some symptoms is a co-incident finding, not the root cause — keep digging or report the gap explicitly.
  4. Assess blast radius. Find other callers/inputs that hit the same defect (Grep for the pattern, referencing symbols). Note data that may already be corrupted if the bug writes state.

    • Completion criterion: every caller of the defective code is classified affected / unaffected.
  5. Propose fix candidates. 1–3 options with tradeoffs (minimal patch vs. proper restructure), the recommended one first, plus the regression test that would have caught this.

Read the full file on GitHub · 62 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. 9d ago First seen · 62 lines · 70 tokens per session scan A b78864b9cc1d

Subscribe to this mod's changes

investigate-bug-report is a skill published in the GitHub repository atman-33/workhub (2 stars, last pushed yesterday), licensed MIT. It adds 70 tokens to every session and 701 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 2026-08-31.

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