Vibe is product logic: How to inject branding into your AI

You probably know exactly how you want your product to vibe — authoritative, playful, formal…

Your AI does not.

To it, there’s only a prompt and a pile of training data.

Here’s how to take the vibe in your head, turn it into concrete rules, and treat that vibe like configuration for your AI.

Vibe is part of the system

Most people treat “vibe” as just colors, copy, and fonts.

In AI products, vibe is product logic. It affects:

• How direct the answers are
• How often it apologizes
• How it reacts when things go wrong

If you don’t set this, the model will invent its own vibe from training data.

Your goal: take the vibe in your head and turn it into simple rules your AI must follow, in:

• System prompts
• Tool prompts
• Safety and escalation rules

We’ll do it in 5 steps.

Step 1 – Write your vibe in plain words

Before anything else, write one sentence that defines your vibe.

It should quickly explain:

• Your tone
• Your purpose
• Your boundaries

Template: “We are a [adjective], [adjective] [product] that helps users [goal] while staying [constraint].”

This line becomes:

• The first line of your Vibe Spec
• The first line of your system prompt

Step 2 – Turn vibe into simple rules

Now turn that sentence into rules your AI can follow.

Use three buckets:

• Always

• Never

• When in doubt

Do this for three areas:

• Tone
• Initiative
• Risk

In all the examples below, we use the same vibe: calm, serious, slightly warm

Tone rules

Always

• Sound calm and serious.
• Be slightly warm (kind), not cold and not “too friendly”.
• Use short, clear sentences.
• Explain hard words in simple language.
• Briefly name user feelings. Example: “I know this can feel stressful.”

Never

• Use emojis.
• Use slang like “lol”, “btw”.
• Use more than one exclamation mark.

When not sure

• Use neutral, straightforward language.
• Do not make jokes.

Initiative rules

Always

• Give 1–3 clear next steps at the end of an answer.

Never

• Make choices for the user without asking.

When not sure

• Ask one simple follow-up question instead of hallucinating.

Risk rules

Always

• Mark uncertain information clearly. Example: “This is an estimate, not a guarantee.”
• Point to places where the user can check the information, like:
• Help center
• Docs
• Account page
• Official website

Never

• Make up numbers or facts.
• Give legal, medical, or tax advice.

When not sure

• Say “I don’t know.”
• Then tell the user what to do next, for example:
  • “Talk to a tax professional.”
  • “Contact support so a human can review it.”

Start with 5–10 rules like these that really change how the AI answers.

Later, you will copy the most important ones into your system prompts and tool prompts.

Step 3 – Build “golden examples”

Golden examples are your reference answers. They show the vibe in real situations.

For each one, write:

• Scenario
• User message
• Bad reply
• Good reply
• Why the good reply is right

Example (compliance)

Scenario: User asks for exact tax and forms.
Bad reply: Gives numbers/forms confidently.
Good reply: Says it can’t do that, explains why, and gives safe next steps (export trades, group gains, list countries) and offers help writing a summary for an accountant.

Why the good reply is right: it follows the rules and avoids fake certainty.

Use these as training data, review examples, and tests.

Step 4 – Write tiny rules for edge cases

Your product’s “feel” is tested in the worst moments, not the best ones. Do not let the base model improvise here.

Pick a few edge cases that matter most for you. For each one, write a very short playbook:

• Goal
• Tone
• Default action

Here’s an angry-user example:

The goal is to calm the user and move toward a clear next step.
The tone should be calm and neutral, with no jokes.
The assistant should notice and name the frustration, restate the problem, offer 1-2 options, and bring in a human when money or security is involved, or when the user specifically asks for a human.

Keep the detailed version in your Vibe Spec so people can see and adjust it. The model only needs the boiled-down version in your prompt, like:

"When the user is angry, briefly acknowledge their frustration, then focus on clear steps to solve the problem. Offer 1-2 options, escalate to a human when the issue involves money, security, repeated failures, or when the user asks, and never argue or make jokes."

Do the same for things like:

• Unsafe or disallowed requests
• User asking you to bend your own rules
• User asking for things you simply do not do

Keep each playbook to a few lines.

Now your vibe works when things go wrong, not only when things are easy.

Step 5 – Inject the vibe into your agent

Up to now, you defined the vibe. Now you make the agent run on it.

You inject it in four places.

1) System prompt (global behavior)

Take your vibe sentence and your most important rules.

Put them in the system prompt.

This controls how the agent sounds and makes decisions by default.

2) Tool prompts (local behavior)

For each key tool, add 1–3 short lines about tone, focus, and limits.

This keeps individual features from drifting.

3) Guardrails (edge cases)

Turn “what to do in edge cases” into rules.

Put them in safety prompts or backend rules.

This tells the agent what to do when things go wrong.

4) Tests

Run your golden examples on the agent.

If the answers don’t look like the “good” ones, change the prompts.

Now the vibe is in the system.