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.
npx skills add dinhanhthi/coding-friend --skill cf-sys-debuggit clone --depth 1 https://github.com/dinhanhthi/coding-friendWrote 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/skills/dinhanhthi/coding-friend/cf-sys-debug)<a href="https://agentmods.dev/skills/dinhanhthi/coding-friend/cf-sys-debug"><img src="https://agentmods.dev/badge/skills/dinhanhthi/coding-friend/cf-sys-debug/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/skills/dinhanhthi/coding-friend/cf-sys-debug"><img src="https://agentmods.dev/badge/skills/dinhanhthi/coding-friend/cf-sys-debug.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 | $0.00136 | $0.02358 |
| Opus 5.5 | $0.00054 | $0.00943 |
| Sonnet 5.5 | $0.00027 | $0.00472 |
| Haiku 4.5 | $0.00014 | $0.00236 |
Grade A, and why
cf-sys-debug 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 — 261 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Systematic Debugging
Custom Guide
bash "<plugin-root>/lib/load-custom-guide.sh" cf-sys-debug
If the block above printed anything, apply only the ## Before, ## Rules, and ## After sections; if it shows the raw command instead of output, re-run that exact load-custom-guide.sh fence now.
Core Constraint
Do not touch code until you can state the root cause in one sentence:
"I believe the root cause is [X] because [evidence]."
Name a specific file, function, and line. Vague labels are not testable. If you cannot be that specific, you do not have a hypothesis yet.
Same symptom after a fix = hard stop. Recurrence or "let me just try this" means the hypothesis is unfinished. Re-read the execution path from scratch before touching code again.
After 3 failed hypotheses, stop. Use the Handoff Format below. Ask how to proceed.
Rationalization Watch
Stop and re-examine when these surface:
| Thought | Rule |
|---|---|
| "I'll just try this one thing" | Write the hypothesis first |
| "I'm confident it's X" | Confidence is not evidence — instrument it |
| "Probably the same issue as before" | Re-read the execution path from scratch |
| "It works on my machine" | Environment difference IS the bug — enumerate every env difference |
| "One more restart should fix it" | Read the last error verbatim. Max two restarts without new evidence |
Progress Signals
Diagnosis is moving when:
- A log line matches the hypothesis → find one more independent piece of evidence
- You can predict the next error → run the prediction
- Cause is in A, symptoms in B → confirm each link in the A→B chain
- You can write a test that would fail on the old code → write it before the fix
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 Changed · -9 lines · +8 tokens per session 7b24b4471066
- 1mo ago First seen · 270 lines · 128 tokens per session scan A f7d85ce1f4f7
cf-sys-debug is a skill published in the GitHub repository dinhanhthi/coding-friend (4 stars, last pushed yesterday), licensed MIT. It adds 136 tokens to every session and 2,358 once invoked, about $0.0005 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 2026-08-31.
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doris-debug-resource-isolation
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doris-debug-compaction
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doris-debug-data-lake
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doris-debug-deployment
Use for Doris FE/BE startup failures, port conflicts, prioritynetworks misrouting, metadir corruption, and ADD/DROP BACKEND issues.
doris-debug-materialized-view
Use for Doris sync MV (rollup) miss or async MTMV refresh/rewrite issues. Commands: SHOW ALTER TABLE MATERIALIZED VIEW, mvinfos(), EXPLAIN, REFRESH MATERIALIZED VIEW.