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 Abilityai/cornelius --skill self-diagnosticgit clone --depth 1 https://github.com/Abilityai/corneliusWrote 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/abilityai/cornelius/self-diagnostic)<a href="https://agentmods.dev/skills/abilityai/cornelius/self-diagnostic"><img src="https://agentmods.dev/badge/skills/abilityai/cornelius/self-diagnostic/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/abilityai/cornelius/self-diagnostic"><img src="https://agentmods.dev/badge/skills/abilityai/cornelius/self-diagnostic.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Agent Snooping · line 103 Skill enumerates or reads other installed skills. Access to other skills' SKILL.md files or the skills directory reveals prompt instructions, capabilities, and secrets that should be invisible to peer skills.Fix: Remove all code or instructions that list or read other skills' files or directories. Skills should operate independently; cross-skill access is a privilege escalation.
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 | $0.00039 | $0.02717 |
| Opus 5 | $0.00019 | $0.01358 |
| Sonnet 5 | $0.00008 | $0.00543 |
| Haiku 4.5 | $0.00004 | $0.00272 |
Grade A, and why
self-diagnostic 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 5d 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 — 369 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cornelius Self-Diagnostic
Run comprehensive diagnostics to verify all agent components are functioning correctly.
Quick Start
Run full diagnostics:
/self-diagnostic
Run specific test category:
/self-diagnostic commands-only
/self-diagnostic skills-only
/self-diagnostic agents-only
/self-diagnostic dependencies-only
State Dependencies
| Source | Location | Read | Write | Description |
|---|---|---|---|---|
| Vault Path | Brain/ |
✓ | Verify vault exists | |
| Permanent Notes Dir | Brain/02-Permanent/ |
✓ | Verify directory exists | |
| Article Index | Brain/04-Output/Articles/ARTICLE-INDEX.md |
✓ | Verify index exists | |
| Local Brain Search | resources/local-brain-search/ |
✓ | Search scripts and index | |
| Skills Directory | .claude/skills/*/SKILL.md |
✓ | Skill configurations | |
| Commands Directory | .claude/commands/*.md |
✓ | Command configurations | |
| Agents Directory | .claude/agents/*.md |
✓ | Agent configurations | |
| Python Runtime | System | ✓ | Verify Python3 available | |
| uv Package Manager | ~/.local/bin/uv |
✓ | Verify uv available | |
| Temp Output | /tmp/cornelius-diagnostic/ |
✓ | Diagnostic results (optional) |
Arguments
$ARGUMENTS
Safety Principles
CRITICAL: These diagnostics are READ-ONLY and NEVER modify production data.
- All tests use read-only operations (search, grep, read)
- NO file creation in Brain/ directory during tests
- NO API calls to paid services (HeyGen, Gemini, etc.)
- Test outputs go to
/tmp/cornelius-diagnostic/only - NO changelog creation during diagnostics
Diagnostic Categories
1. Infrastructure Tests
Verify core infrastructure is accessible:
# Test 1.1: Check vault path exists
test -d "Brain" && echo "PASS: Vault path exists" || echo "FAIL: Vault path missing"
# Test 1.2: Check permanent notes directory
test -d "Brain/02-Permanent" && echo "PASS: Permanent notes directory exists" || echo "FAIL: Permanent notes directory missing"
# Test 1.3: Check Local Brain Search is available
test -f "resources/local-brain-search/run_search.sh" && echo "PASS: Local Brain Search scripts exist" || echo "FAIL: Local Brain Search scripts missing"
# Test 1.4: Check Article Index exists
test -f "Brain/04-Output/Articles/ARTICLE-INDEX.md" && echo "PASS: Article Index exists" || echo "FAIL: Article Index missing"
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.
- 5d ago First seen · 369 lines · 39 tokens per session scan A 86a24697f3be
self-diagnostic is a skill published in the GitHub repository Abilityai/cornelius (106 stars, last pushed 16d ago), licensed MIT. It adds 39 tokens to every session and 2,717 once invoked, about $0.0002 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.
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