validate-design-early

A development rule that asks for design approval before implementing a major feature or writing 100 or more lines for it.

In plain words
What is it for?
Use it when a feature introduces a new subsystem, has several valid designs, or commits the project to an architectural direction.
Why use it?
It helps catch unclear requirements and architectural choices before substantial code is written.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/rethunk-ai/clodbridge/validate-design-early
Clone the repo
git clone --depth 1 https://github.com/Rethunk-AI/clodbridge

Made for: Cursor.

Per session 227 This file is loaded in full into every session.
When invoked 227 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.00227 $0.00227
Opus 5 $0.00113 $0.00113
Sonnet 5 $0.00045 $0.00045
Haiku 4.5 $0.00023 $0.00023

Measured 2d ago against content hash 41c46ebc3e49, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

validate-design-early 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 2d 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/validate-design-early.mdc · 42 lines

What it actually says

Validate Design Early

Before implementing a major feature, confirm the design with the user.

What Counts as Major

  • A new subsystem (file watching, MCP resources, etc.)
  • A design choice with multiple valid approaches
  • A requirement not explicitly stated
  • Any architectural direction you're committing the user to

When to Ask

Before writing 100+ lines for that feature. After planning, before implementing.

How to Ask

Use AskUserQuestion with concrete options:

"Should clodbridge expose MCP Resources (cursor:// URIs)?"
Options:
  A) Yes - users will want direct file access
  B) No - tools are sufficient
  C) Yes, but only for rules

What NOT to Ask

  • Low-level implementation details (map vs object?)
  • Code style (tabs vs spaces?)
  • Questions you can answer from user's prior feedback

For design decision patterns and examples, see the validate-design-early skill.

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. 2d ago First seen · 42 lines · 227 tokens per session scan A 41c46ebc3e49

Subscribe to this mod's changes

validate-design-early is a cursor rule published in the GitHub repository Rethunk-AI/clodbridge (0 stars, last pushed 1mo ago), licensed MIT. It adds 227 tokens to every session, about $0.0011 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.