QR

Generate, customize, and deploy QR codes with proper sizing, error correction, and use-case optimization.

Security Scan

This is an instruction-only QR guidance skill whose requirements and instructions align with its stated purpose and do not request credentials, installs, or unexpected system access.

Purpose & Capability

The name/description (generate, customize, deploy QR codes) matches the SKILL.md, types.md, and deployment.md content. The guidance references short links and tracking, which are expected for QR deployment and do not require additional credentials in the skill itself.

Instruction Scope

Runtime instructions are limited to design, sizing, error correction, testing, and deployment best practices. They do not instruct the agent to read files, access environment variables, or call external endpoints directly.

Install Mechanism

No install spec and no code files — instruction-only. This minimizes disk writes and arbitrary code execution risk.

Credentials

The skill requests no environment variables, credentials, or config paths. References to dynamic QR services and tracking are advisory only; any credential use would occur only if the user chooses third-party services later.

Persistence & Privilege

always is false and the skill does not request persistent system presence or modify other skills/config. Autonomous invocation is allowed by platform default and is not combined with other risk factors here.

Assessment

This skill is low-risk: it's a collection of QR design and deployment best practices and does not ask for credentials or install code. Before using it: (1) be cautious when following its advice to use URL shorteners or analytics — those services may collect click/scan data and require separate accounts/credentials; (2) avoid embedding secrets (WiFi passwords, private payment keys) in QRs that will be publicly visible; (3) when implementing dynamic QRs or payment QRs, use reputable providers and validate regional payment standards; and (4) always test printed QRs at real size and lighting conditions before wide distribution.

Before Generating

1. Choose correct type — URL is not the only option. See types.md for vCard, WiFi, email, SMS, geo, etc.
2. Shorten dynamic URLs — Long URLs = dense codes = harder to scan. Use short links for tracking too.
3. Set error correction — L (7%) for clean environments, M (15%) default, Q (25%) with logos, H (30%) for harsh conditions

Sizing Rules

Minimum sizes by scan distance:

• Phone at arm's length (~30cm): 2x2 cm minimum
• Table tent (~50cm): 3x3 cm
• Poster (~1m): 5x5 cm
• Billboard (~5m): 25x25 cm

Formula: QR size = scan distance ÷ 10

Color & Contrast

• Minimum 70% contrast between foreground and background
• Dark on light ONLY — scanners expect dark modules
• Never invert (white on black fails on many readers)
• Avoid gradients on modules — solid colors only
• Background can have subtle texture if contrast maintained

Testing Checklist

Before printing/deploying:

• Scan with 3+ different phones (iOS, Android old/new)
• Test in target lighting conditions
• Verify destination loads correctly
• Check at actual print size, not screen preview
• Test after any logo/customization applied

Common Failures

Symptom	Cause	Fix
Won't scan	Too small / low contrast	Increase size, check colors
Scans but wrong content	URL changed after print	Use dynamic QR / redirect
Works on some phones	Over-customized, low error correction	Reduce customization, increase EC
Slow to recognize	Too dense	Shorten URL, reduce data

Use Case Guides

Context	See
Data types (WiFi, vCard, etc.)	types.md
Business deployment patterns	deployment.md