TL;DR: Paste one prompt into ChatGPT, pick from 10 modes, get back a structured, reusable prompt every time. No commentary, no filler. Just the output you asked for.
A user on r/PromptEngineering shared a system prompt in Portuguese that turns ChatGPT into a dedicated prompt engineering assistant. They called it a Mini Copilot. It does exactly what the name says. The post picked up serious traction fast, which tells you something: people are tired of prompting by intuition and getting wildly inconsistent results. They want a repeatable system, not a guessing game. This is that system.
What You Get
When you activate the prompt, ChatGPT shows a menu of 10 modes and waits. No intro. No unsolicited explanation. Just this:
- Create Base Prompt
- Refine Existing Prompt
- Fix Prompt with Cognitive Noise
- Create AI Persona
- Structure Intelligent Agent
- Modularize Complex Prompt
- Create Content Production Prompt
- Create Technical/Professional Prompt
- Simulate AI Response
- Diagnose Prompt Failures
You type a number. It executes that mode and nothing else. No extra commentary, no unsolicited advice, no explanation of what it just did. A few of these are worth calling out specifically. “Fix Prompt with Cognitive Noise” targets prompts that are technically complete but full of vague language, conflicting instructions, or ambiguous phrasing that quietly confuses the model into doing something half-right. “Simulate AI Response” lets you preview how ChatGPT would actually respond to a prompt before you deploy it, which matters a lot when you are about to run something at scale or feed it to a client. “Structure Intelligent Agent” goes beyond a simple prompt: it builds a full agent definition with roles, goals, constraints, and output format all locked in from the start.
Why This Actually Works
Every prompt the copilot generates follows the same format: Context, Objective, Rules, Input, Expected Output, wrapped in code blocks. Every single time.
That consistency is the real value. Most prompts fail because they are ambiguous. Instructions that gesture toward an outcome without defining it clearly. This system enforces structure before any generation happens. And structured prompts break less. Context tells the model who it is and what situation it is operating in. Objective pins the exact goal so there is no room for drift. Rules set the guardrails so the model does not invent behavior you did not ask for. Input specifies what you will provide. Expected Output defines what done actually looks like. When all five are present and written clearly, the model has nowhere to go except toward the right answer. Strip any one of those five and you are back to hoping.
Mode 10 (Diagnose Prompt Failures) is worth saving on its own. Instead of staring at a bad output and guessing what went wrong, you hand it to the copilot and get a breakdown of what is broken and why. Maybe the instructions were contradictory. Maybe the context was missing entirely. Maybe the expected output was so vague the model filled in the blanks with something generic and plausible-sounding but useless. Mode 10 surfaces the actual reason, which means you fix the real problem instead of rewriting the whole prompt from scratch and hoping the next version lands better.
🛠 Use Cases
- Building a custom GPT and need a tight, reliable system prompt. Run Mode 1 for a clean base or Mode 5 if you need a full agent structure with constraints and role definition already built in.
- You have a prompt that works sometimes and fails other times. Mode 3 is built for exactly that. It finds the cognitive noise causing the inconsistency and rewrites around it so behavior stabilizes.
- You need to break a 500-word megaprompt into clean, swappable modules. Mode 6 gives you independent blocks you can mix and match without rewriting everything from scratch every time the use case shifts slightly.
- You want to preview how ChatGPT will respond before running a prompt at scale. Mode 9 simulates the output so you catch tone, format, or logic problems before they reach a real user or a real workflow.
Prompt of the Day
The original is in Portuguese. Here is an English version you can paste and use right now:
You are a Prompt Engineering Mini Copilot.
Your job: help me create, refine, diagnose, and optimize prompts for ChatGPT.
Modes:
[1] Create Base Prompt
[2] Refine Existing Prompt
[3] Fix Noisy Prompt (Cognitive Noise)
[4] Create AI Persona
[5] Structure Intelligent Agent
[6] Modularize Complex Prompt
[7] Create Content Production Prompt
[8] Create Technical/Professional Prompt
[9] Simulate AI Response
[10] Diagnose Prompt Failures
Rules:
- Open with the menu only. No explanations.
- Wait for mode selection before doing anything.
- Execute only what the selected mode requires.
- Structure every prompt as: Context / Objective / Rules / Input / Expected Output.
- Deliver all output inside code blocks.
- No extra commentary. No unsolicited advice.
Show the menu now.Paste that into a fresh ChatGPT session. Next time a prompt gives you garbage output, run Mode 10 before you touch a single word. If you have a prompt that works but feels bloated and brittle, Mode 6 will break it into something you can actually maintain. If you are starting from zero, Mode 1 gets you a solid base and Mode 2 tightens it until it holds consistently.
Prompt engineering has real frameworks now. Might as well start using them.
Prompt: MINI COPILOTO DESENVOLVIMENTO DE PROMPTS PARA CHATGPT
by u/Ornery-Dark-5844 in PromptEngineering