What is draw-assembly-diagrams?

A workflow guide for creating and checking mechanical assembly drawings in AutoCAD, a computer-aided design program. It covers drawings stored as DWG or DXF files, PDFs, reference images, parts lists, exploded views, and drawing standards.

Use it to create, inspect, trace, validate, repair, review, and export mechanical assembly drawings and related parts lists.

It provides a defined process for turning specifications or images into checked CAD drawings and for repairing drawings that fail validation.

How LokmenoWer/best-cad-mcp configures Codex

Reuse

Borrowing it

Nothing to install: this file belongs to LokmenoWer/best-cad-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/LokmenoWer/best-cad-mcp/master/.agents/skills/draw-assembly-diagrams/SKILL.md

Clone the repo

git clone --depth 1 https://github.com/LokmenoWer/best-cad-mcp

Made for: Codex.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/lokmenower/best-cad-mcp/draw-assembly-diagrams/github.svg)](https://agentmods.dev/skills/lokmenower/best-cad-mcp/draw-assembly-diagrams)

Your own site

<a href="https://agentmods.dev/skills/lokmenower/best-cad-mcp/draw-assembly-diagrams"><img src="https://agentmods.dev/badge/skills/lokmenower/best-cad-mcp/draw-assembly-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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/lokmenower/best-cad-mcp/draw-assembly-diagrams"><img src="https://agentmods.dev/badge/skills/lokmenower/best-cad-mcp/draw-assembly-diagrams.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 186 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,008 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

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	$0.00186	$0.04008
Opus 5	$0.00093	$0.02004
Sonnet 5	$0.00037	$0.00802
Haiku 4.5	$0.00019	$0.00401

Measured 12d ago against content hash 7e32f7075554, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

draw-assembly-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 12d 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.

.agents/skills/draw-assembly-diagrams/SKILL.md · 360 lines

How it starts

The opening of the file, as written. The whole thing — 360 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Draw Assembly Diagrams

Use this skill as the operating guide for best-cad-mcp. Treat AutoCAD as the source of truth once a DWG exists, external images as hypotheses until converted to validated ImageDrawingSpec/v1, SQLite as model-private CAD memory, prompt/resources as reusable guidance, and CADPlan as the guarded path for multi-step generation or repair.

Reference Routing

Read only the references needed for the task:

Assembly drawing, BOM, item-numbering, section, exploded view, or standards-compliance work: read references/assembly/index.md.
When no project/company/national standard is specified, use references/assembly/standards/generic-mechanical.md as the default mechanical assembly standard module.
references/assembly-drawing-requirements.md is a compatibility entrypoint; prefer the modular assembly references above for new work.
Prompt content should come from repository prompt files through MCP prompt tools. Use copy_drawing_from_image for one-image tracing, precise_draw_from_spec for text/spec generation, vlm_review_drawing for visual review of an existing/exported CAD view, and repair_drawing for validation-led fixes.

Hard Boundaries

Before live CAD work, call check_runtime_environment(check_autocad=True). Treat ok=false as a blocker. For strict deployments, expect CAD_MCP_STRICT_PREFLIGHT=1 to make the server refuse startup when required checks fail.
Use the active best-cad-mcp AutoCAD connection. Do not launch another AutoCAD process.
Do not write standalone Python, VBA, LISP, or pywin32 COM scripts to modify drawings. Add or fix a best-cad-mcp tool when COM behavior is missing.
Understanding, scans, CAD-IR/resource reads, semantic detection, dimension binding, constraints, validation, image trace preparation, VLM grounding, prompt reads, CADPlan validation, fidelity checks, and dry-runs must not modify the DWG.
Editing requires a specific drawing/editing tool call or execute_cad_plan(plan, allow_modify=True) after validation and dry-run.
Treat send_command, modal plotting, screen-pick tools, purge, erase, password, close, and global undo/redo as unsafe unless explicitly requested.
Keep agent memory in SQLite resources, semantic objects, constraints, image trace records, VLM findings, or spatial annotations. Do not create hidden helper layers, XData, blocks, labels, or visible marks for memory.
For one-image copy/tracing, the VLM call stays on the agent side. MCP prepares the image, validates the VLM JSON, compiles CADPlan, and enforces fidelity; it does not call a model provider directly.
Never use draw_raster_image as a substitute for vectorizing/copying a drawing. Use it only when the user explicitly wants a reference underlay.

Read the full file on GitHub · 360 lines

Files

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.

Changes

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.

12d ago First seen · 360 lines · 186 tokens per session scan A 7e32f7075554

Subscribe to this mod's changes

draw-assembly-diagrams is a skill published in the GitHub repository LokmenoWer/best-cad-mcp (12 stars, last pushed 19d ago), licensed MIT. It adds 186 tokens to every session and 4,008 once invoked, about $0.0009 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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best-cad-mcp: Skill for Codex