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 fzfclee/consulting-skills --skill deductive-reasoninggit clone --depth 1 https://github.com/fzfclee/consulting-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/fzfclee/consulting-skills/deductive-reasoning)<a href="https://agentmods.dev/skills/fzfclee/consulting-skills/deductive-reasoning"><img src="https://agentmods.dev/badge/skills/fzfclee/consulting-skills/deductive-reasoning/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/fzfclee/consulting-skills/deductive-reasoning"><img src="https://agentmods.dev/badge/skills/fzfclee/consulting-skills/deductive-reasoning.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 | $0.00058 | $0.00707 |
| Opus 5.5 | $0.00023 | $0.00283 |
| Sonnet 5.5 | $0.00012 | $0.00141 |
| Haiku 4.5 | $0.00006 | $0.00071 |
Grade A, and why
deductive-reasoning 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 — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Deductive Reasoning
Use this skill to test whether a conclusion follows from stated premises, rules, or criteria.
Method Notes
- Deductive reasoning moves from general rules or premises to a specific conclusion.
- A deductive conclusion is only as reliable as the premises and the logic connecting them.
- This method is strongest when rules, definitions, criteria, or constraints are explicit.
- It should separate validity from truth: an argument can be logically valid but built on a false or weak premise.
Required Inputs
Collect or infer these inputs before execution:
- conclusion or decision to test
- stated rules, criteria, principles, policies, or premises
- facts of the specific case
- scope boundary
- exceptions or override conditions
If an input is missing, mark it as missing, state the assumption used, and add a validation action.
When Not To Use
Do not use when there are no clear premises or rules and the task is pattern discovery. Use inductive-reasoning, abductive-reasoning, or affinity-diagram first.
Step-by-Step Execution
| Step | Required input | How to execute | Output |
|---|---|---|---|
| State the conclusion | Decision, claim, or recommendation. | Write the conclusion in one testable sentence. | Conclusion to test. |
| List premises | Rules, criteria, policies, principles, definitions. | Separate general premises from case-specific facts. | Premise list. |
| Check premise quality | Source, evidence, authority, scope. | Mark each premise as strong, medium, weak, or missing. | Premise quality table. |
| Map logic chain | Premises, case facts, conclusion. | Build the if-then path from premises to conclusion. | Logic chain. |
| Test validity | Logic chain, exceptions. | Check whether the conclusion necessarily follows if premises are true. | Validity judgment. |
| Check exceptions | Scope, edge cases, override conditions. | Identify conditions that weaken or reverse the conclusion. | Exception list. |
| Rewrite conclusion | Validity and premise quality. | State a careful conclusion that matches the actual logic strength. | Revised conclusion. |
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 · 77 lines · 58 tokens per session scan A 55ba5b630965
deductive-reasoning is a skill published in the GitHub repository fzfclee/consulting-skills (7 stars, last pushed 15d ago), licensed Apache-2.0. It adds 58 tokens to every session and 707 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 2026-08-31.
Other skills, from other repositories
apply-insight-synthesis
Use when you've gathered a substantial body of research or data and are about to write up or present it — stop gathering, cluster the findings by underlying pattern rather than by source or chronology, and repeatedly ask "so what does this mean for the decision" until you reach a small number of specific, actionable…
taxue
A main entry point for a decision-support system that asks questions, clarifies what you really need, and guides you toward an action.
taxue-learn
A learning method that turns information into usable understanding through four stages of practice and internalisation. It includes approaches such as the Feynman technique, which means explaining an idea simply to test your understanding.
taxue-diagnosis
A structured diagnosis method that examines a situation through quick, detailed, or multiple-perspective reviews. It covers life planning, business viability, business models, and possible blind spots.
taxue-job-search
A job-listing search service that looks for real open positions by location, education requirements, and employer type, then checks information across multiple sources.
taxue-solve
A thinking aid that turns a vague problem or difficult choice into a clear plan of action. It first examines what the real problem is, including whether emotions are hiding the main question.