design-standards

design-standards is a cursor rule for Cursor from jim-schilling/splurge-ai-rules. It costs 4 tokens per session (305 once invoked), scanned A, original, MIT.

A set of software design guidelines covering simplicity, limited responsibilities, reuse, error handling, and security boundaries. It also explains BDD and TDD, development methods that use expected behavior or tests to guide implementation.

In plain words
What is it for?
Use it when designing or reviewing modules, functions, dependencies, error paths, object relationships, and the scope of a new feature.
Why use it?
It helps keep code understandable and avoids duplicated, overcomplicated, unsafe, or prematurely expanded designs.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use it when designing or reviewing modules, functions, dependencies, error paths, object relationships, and the scope of a new feature.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/jim-schilling/splurge-ai-rules/design-standards
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/jim-schilling/splurge-ai-rules

Made for: Cursor.

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.

agentmods badge for design-standards

README.md
[![agentmods](https://agentmods.dev/badge/rules/jim-schilling/splurge-ai-rules/design-standards/github.svg)](https://agentmods.dev/rules/jim-schilling/splurge-ai-rules/design-standards)
Your own site
<a href="https://agentmods.dev/rules/jim-schilling/splurge-ai-rules/design-standards"><img src="https://agentmods.dev/badge/rules/jim-schilling/splurge-ai-rules/design-standards/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.

agentmods 80×15 button for design-standards

Your own site · 80×15
<a href="https://agentmods.dev/rules/jim-schilling/splurge-ai-rules/design-standards"><img src="https://agentmods.dev/badge/rules/jim-schilling/splurge-ai-rules/design-standards.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 4 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 305 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00004 $0.00305
Opus 5 $0.00002 $0.00152
Sonnet 5 $0.00001 $0.00061
Haiku 4.5 $0.00000 $0.00030

Measured 8d ago against content hash 642d7c8d3bde, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

design-standards 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 8d 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.

.cursor/rules/design-standards.mdc · 28 lines

What it actually says

  • Follow SOLID (Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, Dependency Inversion) principles.
  • Follow DRY (Don't Repeat Yourself) principle.
  • Follow BDD/TDD (Behavior/Test Driven Development) practices.
  • Follow MVP (Minimum Viable Product) approach.
  • Follow KISS (Keep It Simple, Stupid) principle.
  • Follow PoLA (Principle of Least Authority).
  • Follow YAGNI (You Aren't Gonna Need It) principle.
  • Prefer composition over inheritance.
  • Prefer encapsulation.
  • Prefer separation of concerns.
  • Prefer to fail fast.
  • Follow the Law of Demeter - objects should only interact with their immediate dependencies.
  • Prioritize error handling using appropriate mechanisms (exceptions, return values, Result types, or callbacks).
  • Use guard clauses to handle preconditions and invalid state early.
  • Avoid side effects in module-level code.
  • Place the happy path (main successful execution flow) last in the function.
  • Use guard clauses and early returns instead of complex if-else chains.
  • Prefer iteration and modularization over code duplication.
  • Prefer simple, straightforward design over over-engineering.
  • Private methods should accept necessary data as parameters rather than directly accessing instance variables.
  • Use domain-specific custom exceptions for public APIs.
  • Use native/built-in exceptions for low-level APIs, where appropriate.
  • Prioritize code clarity while maintaining reasonable efficiency.
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.

  1. 8d ago First seen · 28 lines · 4 tokens per session scan A 642d7c8d3bde

Subscribe to this mod's changes

design-standards is a cursor rule published in the GitHub repository jim-schilling/splurge-ai-rules (3 stars, last pushed 11mo ago), licensed MIT. It adds 4 tokens to every session and 305 once invoked, about $0.0000 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.