---
name: principle-prove-it-works
description: Verify the requested behavior against the real artifact or surface whenever possible; a proxy check only proves the proxy. Use when verifying changes, completing tasks, or claiming something is fixed.
---
# Prove It Works

## Trigger

When verifying changes, completing tasks, or claiming something is fixed.

## Rule

Verify the requested behavior against the real artifact or surface whenever possible; a proxy check only proves the proxy.

## Application

1. Name the concrete decision this principle changes.
2. Apply the rule to that decision, not as a decorative citation.
3. Prefer evidence from the current repository/runtime over generic preference.
4. If the principle conflicts with an explicit user constraint, keep the constraint and state the tradeoff.