Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add terrylica/cc-skills/plugin install doc-toolsWrote 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/terrylica/cc-skills/teachback)<a href="https://agentmods.dev/skills/terrylica/cc-skills/teachback"><img src="https://agentmods.dev/badge/skills/terrylica/cc-skills/teachback/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/terrylica/cc-skills/teachback"><img src="https://agentmods.dev/badge/skills/terrylica/cc-skills/teachback.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 | $0.00066 | $0.08408 |
| Opus 5.5 | $0.00026 | $0.03363 |
| Sonnet 5.5 | $0.00013 | $0.01682 |
| Haiku 4.5 | $0.00007 | $0.00841 |
Grade A, and why
teachback scanned grade A with 1 finding 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 20d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
`integrity` pins the bytes, not merely the URL: a swapped or compromised CDN object fails to execute rather than running silently. Recompute it if the pinned version changes — `curl -sSL <url> | openssl dgst -sha384 -bin How it starts
The opening of the file, as written. The whole thing — 408 lines — stays where its author put it; the contents beside it link to each section on GitHub.
teachback — teach the material back as a self-contained interactive page
Self-Evolving Skill: this file improves through use. If an instruction here is wrong, a gate rejected a page it should have accepted, or you needed a workaround — fix this file immediately, don't defer. Only for real, reproducible issues. And when you add a check to a gate, add the mutation that proves it can fail: an unexercised check is not yet a check.
Produces one HTML file that explains hard material to an intelligent reader with no assumed specialist background. The page runs from file:// with no server, no tracking and no framework.
The defining behaviour: teachback reads what is already in the working context. Do not ask the reader to restate material the conversation already contains. Infer the subject, scope, prerequisites, title, filename and technical depth.
This copy is canonical. teachback was built in
example-org/research-repoand merged there as #527 after eleven review rounds; it was promoted to terrylica/cc-skills on 2026-08-20 to make it available in every project rather than one repository. Edit it here. The research-repo path.claude/skills/teachback/is being reduced to a redirect stub carrying no gate scripts; until that lands, two full copies exist and only this one is authoritative. If you find yourself editing the research-repo copy, stop and edit this one.
Options
Every option is optional. /teachback with no arguments is the common case.
| Option | Effect |
|---|---|
| (none) | Explain the most recent coherent discussion in the working context. |
<subject> |
Explain a named subject instead, e.g. /teachback the spanning admission result. |
--source <path|issue|url> |
Explain designated material rather than the conversation: a file, #123, a doc path, a URL. |
--out <path> |
Write the page here. Default: ~/Documents/explainers/<slug>.html, outside the repository — generated pages are artefacts, not source. Pass an in-repo path only when the page is meant to be committed. |
--update <path> |
Revise an existing page in place instead of creating one. Implied by --terms and --revise. |
--terms "a, b, c" |
The terminology loop. Add or substantially deepen coverage of these terms in an existing page. This is what the page's own footer form emits. |
--revise "<instruction>" |
Any other change to an existing page, in plain language. |
--depth intro|standard|deep |
How much advanced qualification to carry. Default standard. deep keeps every limitation, objection and open question. |
--questions <n> |
Assessment size. Default 3–8, chosen to cover the objectives. |
--open / --no-open |
Launch the default browser on completion. Default --open. |
--dark / --light |
Force a colour scheme. Default: follow the operating system. |
What ships with it
4 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.
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.
- 20d ago Changed · -222 lines a3345139578a
- 1mo ago First seen · 630 lines · 66 tokens per session scan A 1f44872d5047
teachback is a skill published in the GitHub repository terrylica/cc-skills (1 stars, last pushed today), licensed MIT. It adds 66 tokens to every session and 8,408 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.
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