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 yarikleto/claude-teacher-plugin/plugin install claude-teacherWrote 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/yarikleto/claude-teacher-plugin/excalidraw)<a href="https://agentmods.dev/skills/yarikleto/claude-teacher-plugin/excalidraw"><img src="https://agentmods.dev/badge/skills/yarikleto/claude-teacher-plugin/excalidraw/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/yarikleto/claude-teacher-plugin/excalidraw"><img src="https://agentmods.dev/badge/skills/yarikleto/claude-teacher-plugin/excalidraw.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 | $0.00104 | $0.02994 |
| Opus 5 | $0.00052 | $0.01497 |
| Sonnet 5 | $0.00021 | $0.00599 |
| Haiku 4.5 | $0.00010 | $0.00299 |
Grade A, and why
excalidraw 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 2d 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 — 316 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Requested topic/task: $ARGUMENTS
Before accessing education data, read ${CLAUDE_PLUGIN_ROOT}/references/education-data.md. Resolve every <education-db> below using that contract. Current session ID: ${CLAUDE_SESSION_ID}.
Excalidraw Diagram
Generate .excalidraw JSON files with detailed educational explanations. Produces interactive, editable diagrams the student can open in excalidraw.com or the VS Code Excalidraw extension.
Invocation
/claude-teacher:excalidraw <concept description>
Philosophy
Diagrams Should ARGUE, Not DISPLAY
A diagram is not a picture — it is a visual argument. Every shape, arrow, and color must advance the student's understanding. If an element does not teach something, remove it.
Isomorphism Test
If you removed ALL text from the diagram, would the spatial structure alone communicate the concept? The layout, grouping, arrow directions, and color coding should carry meaning independently of labels.
Education Test
Could someone who knows nothing about this topic learn something concrete from this diagram? Not just "see a pretty picture" but actually understand a relationship, flow, or structure they did not understand before.
Reference Files (Read Before Generating)
Before generating any diagram, read these reference files:
${CLAUDE_SKILL_DIR}/references/color-palette.md— semantic color system, text colors, sizing${CLAUDE_SKILL_DIR}/references/element-templates.md— copy-paste JSON for every element type${CLAUDE_SKILL_DIR}/references/json-schema.md— property tables, binding rules, options
These files contain the exact hex codes, JSON templates, and schema details needed to produce valid diagrams. Do not rely on memory — read them.
Depth Assessment
Before building, assess the complexity the student needs:
Simple / Conceptual
- Abstract shapes, overview flows, high-level architecture
- 5-15 elements total
- No evidence artifacts needed
- One zoom level
What ships with it
3 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.
- 2d ago Changed · +4 lines · +15 tokens per session 4faae6c1ad25
- 10d ago First seen · 312 lines · 89 tokens per session scan A c8b7fd1e110a
excalidraw is a skill published in the GitHub repository yarikleto/claude-teacher-plugin (8 stars, last pushed 4d ago), licensed MIT. It adds 104 tokens to every session and 2,994 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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