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 chgagne/claude-skills-research --skill explaining-derivationsgit clone --depth 1 https://github.com/chgagne/claude-skills-researchWrote 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/chgagne/claude-skills-research/explaining-derivations)<a href="https://agentmods.dev/skills/chgagne/claude-skills-research/explaining-derivations"><img src="https://agentmods.dev/badge/skills/chgagne/claude-skills-research/explaining-derivations/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/chgagne/claude-skills-research/explaining-derivations"><img src="https://agentmods.dev/badge/skills/chgagne/claude-skills-research/explaining-derivations.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 | $0.00109 | $0.04069 |
| Opus 5 | $0.00055 | $0.02034 |
| Sonnet 5 | $0.00022 | $0.00814 |
| Haiku 4.5 | $0.00011 | $0.00407 |
Grade A, and why
explaining-derivations 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 — 306 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Explaining Derivations
Overview
An expansion that cannot be completed is evidence against the derivation.
That is the thesis, and it is what separates this skill from pedagogy. Making a proof explicit is useful in itself — but the moment a step resists being made explicit, you have learned something about the proof rather than about the reader. A step nobody can justify leaves this skill as a gap-ledger row with a severity, and that ledger feeds back into the review as findings.
So the deliverable is two things at once: a standalone LaTeX document per theorem, readable by an undergraduate engineer or an ML graduate student without formal maths training, and a ledger of every step that could not be written down.
Core principle: never manufacture a justification. The register that reads best is also the one that most invites a plausible-sounding reason for a step nobody checked. Every guard below exists for that.
Run it
python3 ~/.claude/skills/explaining-derivations/assets/run-explain.py main.tex \
--out derivations/ --level grad-ml --plan-only
Run it by absolute path from the paper directory. Stdlib only — no install, no
venv. latexmk is used if present, never installed; absent, the .tex is still
written and the run exits 2.
--plan-onlyfirst, always. A dozen theorems is a dozen subagents. It prints the plan and dispatches nothing.--level undergrad | grad-ml | expert-shorthand— seereference/registers.md--verdicts review-assets/proofsteps.csv— verdicts fromverifying-proofs. Without them every Checked cell reads not run, and the expander is forbidden to write one it did not receive--claims thm:main·--only-flagged·--all-gaps·--no-pdf
Outputs into --out: <label>.tex and .pdf per theorem, index.md,
gaps.json, requests/*.json, and preamble.tex copied in so the artifact still
builds after this skill is gone.
The workflow is three phases, not one command
What ships with it
29 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- assets/explain/__init__.py 0 B runs code
- assets/explain/__main__.py 7.9 KB runs code
- assets/explain/assemble.py 15 KB runs code
- assets/explain/build.py 4.5 KB runs code
- assets/explain/fragment.py 12 KB runs code
- assets/explain/gaps.py 3.9 KB runs code
- assets/explain/ledger_io.py 3.1 KB runs code
- assets/explain/notation.py 7.2 KB runs code
- assets/explain/report.py 3.5 KB runs code
- assets/explain/triage.py 10 KB runs code
- assets/run-explain.py 675 B runs code
- assets/templates/derivation.tex.in 1.7 KB
- assets/templates/preamble.tex 4.4 KB
- assets/tests/fixtures/bubeck-lem-smoothconst-gaps-run3.json 4.5 KB
- assets/tests/fixtures/bubeck-lem-smoothconst-verdicts.json 780 B
- assets/tests/fixtures/bubeck-lem-smoothconst.json 14 KB
- assets/tests/fixtures/bubeck-lem-smoothconst.tex 1.1 KB
- assets/tests/test_assemble.py 15 KB runs code
- assets/tests/test_dispatch_acceptance.py 14 KB runs code
- assets/tests/test_expander_agreement.py 5.9 KB runs code
- assets/tests/test_expansion_replay.py 7.5 KB runs code
- assets/tests/test_fragment.py 11 KB runs code
- assets/tests/test_ledger_io.py 3.3 KB runs code
- assets/tests/test_stdlib_only.py 1.8 KB runs code
- assets/tests/test_triage.py 16 KB runs code
- reference/gap-ledger.md 4.2 KB
- reference/move-vocabulary.md 5.4 KB
- reference/registers.md 4.1 KB
- reference/subagent-contract.md 9.7 KB
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 · 306 lines · 109 tokens per session scan A 36ef67776b4a
explaining-derivations is a skill published in the GitHub repository chgagne/claude-skills-research (4 stars, last pushed 6d ago), licensed MIT. It adds 109 tokens to every session and 4,069 once invoked, about $0.0005 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 2026-08-31.
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