Borrowing it
Nothing to install: this file belongs to luanmorenommaciel/agentspec. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/luanmorenommaciel/agentspec/main/.claude/skills/excalidraw-diagram/SKILL.mdgit clone --depth 1 https://github.com/luanmorenommaciel/agentspecWrote 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/luanmorenommaciel/agentspec/excalidraw-diagram)<a href="https://agentmods.dev/skills/luanmorenommaciel/agentspec/excalidraw-diagram"><img src="https://agentmods.dev/badge/skills/luanmorenommaciel/agentspec/excalidraw-diagram/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/luanmorenommaciel/agentspec/excalidraw-diagram"><img src="https://agentmods.dev/badge/skills/luanmorenommaciel/agentspec/excalidraw-diagram.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 2 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high Anti-Refusal · line 501 Skill instructs the agent to omit warnings, disclaimers, or ethical commentary. Stripping safety caveats hides risk from the user and is a common jailbreak preamble.Fix: Remove instructions that suppress warnings, disclaimers, or ethical commentary. Let the agent surface safety-relevant caveats to the user.
- medium Prompt Injection · line 250 Subtle instructions detected that may alter agent decision-making or introduce hidden biases.Fix: Review content for implicit steering or bias. Ensure instructions are explicit and align with the skill's stated purpose.
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 | $0.00034 | $0.05475 |
| Opus 5 | $0.00017 | $0.02738 |
| Sonnet 5 | $0.00007 | $0.01095 |
| Haiku 4.5 | $0.00003 | $0.00547 |
Grade B, and why
excalidraw-diagram scanned grade B 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 10d 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.
Subtle steeringmediumPrompt injection
Instructions that bias recommendations or shape behaviour without the user noticing.
- **Don't write a Python generator script.** The templating and coordinate math seem helpful but introduce a layer of indirection that makes debugging harder. Hand-crafted JSON with descriptive IDs is more maintainable. Copies of this mod
5 near-identical copies found in the catalogue:
- excalidraw-diagram — 97% identical, 6 lines differ
- excalidraw-diagram — 97% identical, 2 lines differ
- excalidraw-diagram — 94% identical, 190 lines differ
- excalidraw-diagram — 91% identical, 324 lines differ
- excalidraw-diagram — 84% identical, 323 lines differ
How it starts
The opening of the file, as written. The whole thing — 553 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Excalidraw Diagram Creator
Generate .excalidraw JSON files that argue visually, not just display information.
Setup: Ensure the required dependencies are available in the environment. See the First-Time Setup section below (under Render & Validate) for the exact install commands.
Customization
All colors and brand-specific styles live in one file: references/color-palette.md. Read it before generating any diagram and use it as the single source of truth for all color choices — shape fills, strokes, text colors, evidence artifact backgrounds, everything.
To make this skill produce diagrams in your own brand style, edit color-palette.md. Everything else in this file is universal design methodology and Excalidraw best practices.
Core Philosophy
Diagrams should ARGUE, not DISPLAY.
A diagram isn't formatted text. It's a visual argument that shows relationships, causality, and flow that words alone can't express. The shape should BE the meaning.
The Isomorphism Test: If you removed all text, would the structure alone communicate the concept? If not, redesign.
The Education Test: Could someone learn something concrete from this diagram, or does it just label boxes? A good diagram teaches—it shows actual formats, real event names, concrete examples.
Depth Assessment (Do This First)
Before designing, determine what level of detail this diagram needs:
Simple/Conceptual Diagrams
Use abstract shapes when:
- Explaining a mental model or philosophy
- The audience doesn't need technical specifics
- The concept IS the abstraction (e.g., "separation of concerns")
Comprehensive/Technical Diagrams
Use concrete examples when:
- Diagramming a real system, protocol, or architecture
- The diagram will be used to teach or explain (e.g., YouTube video)
- The audience needs to understand what things actually look like
- You're showing how multiple technologies integrate
For technical diagrams, you MUST include evidence artifacts (see below).
What ships with it
7 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.
- 10d ago First seen · 553 lines · 34 tokens per session scan B ae6b1afe42db
excalidraw-diagram is a skill published in the GitHub repository luanmorenommaciel/agentspec (246 stars, last pushed 2d ago), licensed MIT. It adds 34 tokens to every session and 5,475 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it B with 1 finding (subtle steering). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.
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