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.
git clone --depth 1 https://github.com/danielvm-git/bigpowersWrote 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.
[](https://agentmods.dev/rules/danielvm-git/bigpowers/investigate-bug)<a href="https://agentmods.dev/rules/danielvm-git/bigpowers/investigate-bug"><img src="https://agentmods.dev/badge/rules/danielvm-git/bigpowers/investigate-bug/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.
<a href="https://agentmods.dev/rules/danielvm-git/bigpowers/investigate-bug"><img src="https://agentmods.dev/badge/rules/danielvm-git/bigpowers/investigate-bug.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00059 | $0.01246 |
| Opus 5.5 | $0.00024 | $0.00498 |
| Sonnet 5.5 | $0.00012 | $0.00249 |
| Haiku 4.5 | $0.00006 | $0.00125 |
Grade A, and why
investigate-bug 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.
How it starts
The opening of the file, as written. The whole thing — 127 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Investigate Bug
Boundary: End-to-end bug entry point — history check → RCA (via diagnose-root) → fix approach → TDD plan → bug file. Delegates the 4-phase RCA to diagnose-root; does not re-implement it.
Investigate a reported problem, find its root cause, and write a TDD fix plan to specs/bugs/BUG-*.md. This is a mostly hands-off workflow — minimize questions to the user.
Process
0. Read previous bug history
Before starting diagnosis:
- Read
specs/bugs/registry.yaml(if it exists) — check for prior bugs in the samescopeor with similar symptoms. - If a relevant prior bug is found, read the corresponding
specs/bugs/BUG-*.mdfile to understand previous root cause analysis and fix approach. - Note in your investigation whether this is a recurrence, a related issue, or novel.
1. Capture the problem
Get a brief description of the issue from the user. If they haven't provided one, ask ONE question: "What's the problem you're seeing?"
Do NOT ask follow-up questions yet. Start investigating immediately.
Security-impact assessment — After capturing the problem, assess and document:
Security impact: NONE / LOW / MEDIUM / HIGH / CRITICAL. If HIGH or CRITICAL, assign bug severity HIGH and document the exploit path in findings. If MEDIUM+, include exploit path in the bug file. Document "no security exploit path identified" for NONE/LOW.
2. Explore and diagnose (4-phase RCA)
Run the 4-phase root-cause analysis via the diagnose-root skill (Reproduce → Isolate → Hypothesize → Verify). That skill is the canonical RCA engine — do not re-implement the phases here.
Also look at:
- Recent changes to affected files (
git log --oneline <file>) - Existing tests (what's tested, what's missing)
- Similar patterns elsewhere in the codebase that work correctly
HARD GATE — Do NOT proceed to Step 3 (Fix Approach) until
diagnose-rootPhase 4 produces a verified root cause. "It probably is X" is not verified.
3. Identify the fix approach
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.
- 1mo ago First seen · 127 lines · 59 tokens per session scan A 7154a17dadb1
investigate-bug is a cursor rule published in the GitHub repository danielvm-git/bigpowers (267 stars, last pushed 27d ago), licensed MIT. It adds 59 tokens to every session and 1,246 once invoked, about $0.0002 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 2026-09-03.
Other cursor rules, from other repositories
bug-fix-tdd-guard
A rule for fixing software bugs with test-driven development, or TDD: first reproduce the bug, then write a test that fails, then make the smallest code change that passes it, and finally run the full checks.
chaos
Failure injection mode — stress test implementations by simulating failures and hostile conditions.
testing-and-safety
TDD bias; no secrets in code; new logic needs unit tests.
bug-fix
Light skill: TDD pipeline for bug fixes. Regression test first, then fix. Can auto-invoke when the user reports a bug, describes unexpected behavior, or asks to fix an issue.
ponytail
Ponytail, lazy senior dev mode. Always pick the simplest solution that works.
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.