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 Liberty91LTD/cti-skills --skill achgit clone --depth 1 https://github.com/Liberty91LTD/cti-skillsWrote 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/liberty91ltd/cti-skills/ach)<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/ach"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/ach/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/liberty91ltd/cti-skills/ach"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/ach.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 | $0.00029 | $0.01047 |
| Opus 5 | $0.00015 | $0.00524 |
| Sonnet 5 | $0.00006 | $0.00209 |
| Haiku 4.5 | $0.00003 | $0.00105 |
Grade A, and why
ach 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 11d 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 — 122 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Analysis of Competing Hypotheses (ACH)
ACH is the most important structured analytic technique for CTI. It forces you to evaluate ALL plausible hypotheses against ALL significant evidence, reducing the impact of cognitive biases — especially confirmation bias.
When to Use ACH
- Attribution questions: "Who is behind this campaign?"
- Ambiguous situations: Multiple plausible explanations exist
- High-stakes assessments: Getting it wrong has significant consequences
- Contested analysis: Analysts disagree on the conclusion
Step-by-Step Procedure
Step 1: Generate Hypotheses
List ALL reasonable hypotheses. Include unlikely ones — the point is to avoid premature narrowing.
Rules:
- Minimum 3 hypotheses (if you only have 2, you're doing binary thinking)
- Include at least one that challenges your initial instinct
- Hypotheses should be mutually exclusive where possible
- Include "unknown actor" or "coincidence" as hypotheses when appropriate
Step 2: List Significant Evidence
Enumerate all evidence and arguments relevant to the hypotheses.
For each piece of evidence, record:
- Description of the evidence
- Source (with Admiralty Scale rating)
- Whether it's direct evidence, circumstantial, or absence of evidence
Step 3: Build the Consistency Matrix
Mark each cell as:
- C (Consistent) — evidence supports this hypothesis
- I (Inconsistent) — evidence contradicts this hypothesis
- NA (Not Applicable) — evidence is irrelevant to this hypothesis
Matrix Template
| Evidence | Source Rating | H1: [Name] | H2: [Name] | H3: [Name] | H4: [Name] |
|----------|:---:|:---:|:---:|:---:|:---:|
| E1: [description] | B2 | C | I | C | NA |
| E2: [description] | A1 | C | C | I | C |
| E3: [description] | C3 | I | C | C | NA |
| E4: [description] | B2 | C | I | I | C |
| E5: [description] | D4 | C | C | C | I |
| **Inconsistencies** | | **1** | **2** | **2** | **1** |
Step 4: Analyse the Matrix
Critical principle: Focus on DISPROVING hypotheses, not proving them.
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.
- 11d ago First seen · 122 lines · 29 tokens per session scan A e7388b69849d
ach is a skill published in the GitHub repository Liberty91LTD/cti-skills (18 stars, last pushed 1mo ago), licensed MIT. It adds 29 tokens to every session and 1,047 once invoked, about $0.0001 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 2026-08-30.
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