Borrowing it
Nothing to install: this file belongs to sean-galloway/RTLDesignSherpa. 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/sean-galloway/RTLDesignSherpa/main/.claude/skills/block-diagrams/SKILL.mdgit clone --depth 1 https://github.com/sean-galloway/RTLDesignSherpaWrote 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/sean-galloway/rtldesignsherpa/block-diagrams)<a href="https://agentmods.dev/skills/sean-galloway/rtldesignsherpa/block-diagrams"><img src="https://agentmods.dev/badge/skills/sean-galloway/rtldesignsherpa/block-diagrams/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/sean-galloway/rtldesignsherpa/block-diagrams"><img src="https://agentmods.dev/badge/skills/sean-galloway/rtldesignsherpa/block-diagrams.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 | $0.00079 | $0.00436 |
| Opus 5.5 | $0.00032 | $0.00174 |
| Sonnet 5.5 | $0.00016 | $0.00087 |
| Haiku 4.5 | $0.00008 | $0.00044 |
Grade A, and why
block-diagrams 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 yesterday.
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.
What it actually says
block-diagrams
READ FIRST: vault/handbook/INDEX.md (the handbook is the repo's memory; this skill is the signpost). Canonical: vault/handbook/authoring/block-diagrams.md - rules in priority order, the element key, layout recipes, the per-shape rulings and the failures behind them.
The rules that get violated most:
- Copy the reference, do not retype it:
vault/handbook/authoring/assets/block-diagrams/axi_plane.dot. - Shape and fill name the class. Interface rounded green, logic white, Registered double border blue, FSM diagonals peach, Storage cylinder lavender, pick trapezium gold, optional dashed. Classify from the RTL.
- A FIFO or skid child instance is a Storage cylinder (owner, 2026-10-25), whatever its output timing; the block whose outputs leave through it is Registered. See "Child instances" in the note.
- The key is GENERATED. Render with
bin/render_block_diagram.py X.dot(or the directory'sregenerate_all_graphviz.sh), never a hand-drawncluster_key. - Render, then read the PNG at full resolution: no text on a line, every flow traceable, every arrow labeled with what it carries.
The handbook root is vault/handbook/INDEX.md - design/, dv/, fpga/, authoring/ areas, atomic notes, wikilinked. When you learn a durable lesson in this domain, ADD IT TO THE HANDBOOK NOTE ([[block-diagrams]]), not to this skill.
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.
- yesterday First seen · 30 lines · 79 tokens per session scan A f0e37e2d9a51
block-diagrams is a skill published in the GitHub repository sean-galloway/RTLDesignSherpa (25 stars, last pushed 2d ago), licensed MIT. It adds 79 tokens to every session and 436 once invoked, about $0.0003 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 2026-10-27.
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