Introduction
In this walkthrough, we’ll build a new Custom Agent for a fictional brand: Ambrosia — a nostalgic, small-batch ice cream company with a playful tone and a growing flavour list.
Our goal is to create a Seasonal Copywriter Agent: someone who can take simple flavour names and write scroll-stopping social ad copy that reflects Ambrosia’s voice.
We’ll create the agent entirely from scratch (rather than duplicating an existing one), and rely on the brand’s library and embedded tone guidance to keep things consistent.
Step 1: What do you want your Agent to do?
We want this Agent to:
Generate short ad copy for seasonal flavours (to be provided).
Referring to the Brand Library, capture Ambrosia’s evocative and beckoning tone, appealing to the reader on an emotional level and capturing their imagination.
Improvise flavour details based on name only.
Sample input:
Write ad copy for these three new flavours:
Salted Honeycomb Swirl
Banana French Toast
Lemon Sherbet Snap
Expected Output:
Short, engaging 1–2 sentence social ad copy for each flavour.
Step 2: Manual Setup
In this guide we are not going to use an initial prompt but will create the agent from scratch. So, after pressing 'Create Agent' we will press 'Skip' in the popup:
Before building your custom agent, it helps to clearly define what it’s for. In this example, we’re creating a Seasonal Copywriter for Ambrosia - a luxury ice cream brand with a nostalgic, indulgent tone.
This agent’s role is to write short, on-brand ad copy for new seasonal flavours. It’s designed to help the marketing team turn simple flavour names into short, sensory-rich copy for ads and social posts - lines that stop the scroll and evoke exactly the right feeling.
This can form the 'Description', and we then need to populate the 'Instructions' field with the specific instructions and expectations we have for the new Agent:
You are Ambrosia’s Seasonal Copywriter.
Your role is to craft short-form, evocative copy for seasonal ice cream flavours aimed at millennial dessert lovers. Always follow the Ambrosia Brand Library - in particular the Knowledge and Tone sections.
Key expectations:
Use language that reflects Ambrosia’s brand persona: indulgent, sophisticated, premium, and gently whimsical
Beckon, don’t instruct - avoid hard CTAs and instead inspire imagination and desire
Use sensory, emotional language (e.g. creamy, velvety, heavenly, divine)
Focus on the feeling of the experience, not the technical product details
You will be given flavour names only. Draw on the brand’s voice and existing tone to create 1–2 sentence copy that makes each flavour feel irresistible and emotionally resonant. Infer any needed details - taste, texture, occasion - in a way that feels natural and on-brand.
The agent needs specific, actionable instructions to guide its output. For Ambrosia, the brand voice is already well-defined in the Brand Library. We’ll include some tone cues and copy rules into the Instructions field, while explicitly instructing it to reference the Brand Library.
Although different agents serve different purposes it is important in the case of this one to include:
Defined output: 'short-form, evocative copy', 'create 1–2 sentence copy'
Target audience: 'millennial dessert lovers'
Explicit reference to the Brand Library, with Knowledge and Tone being most critical when considering copy
Defined input: 'You will be given flavour names only.'
We will choose the GPT-4o model for a balance of creativity and brand alignment.
Additional settings
Finally, we have added an optional 'Conversation starter', and just checked the 'Brand Knowledge' box to give the Agent access to the Brand Guidelines.
'Visit URL' and 'Web Access' are deliberately left unchecked in this case. The Agent doesn't need external data - just a Flavour Name and the Brand Library are sufficient.
The agent's underlying model draws on its existing knowledge of food, language, and sensory detail to imagine textures, moods, and occasions. This keeps the output consistent with Ambrosia’s tone and avoids pulling in factual (but off-brand) content from the web.
Preview
The box on the right of the configuration panel shows a preview of your Agent and you can test it out. I inputted a flavour 'Salted Honeycomb Swirl' and my Agent generated the following copy:
Publishing and Using
Based on the initial output I proceeded to Publish the new Agent and it is now viewable and can be accessed from the main Agents screen. Opening it, we are met with my Conversation starter:
I tested it out with some other new flavours:
The Agent then offers a follow up question un-prompted regarding integration into marketing which, after responding with Yes, suggests the following:
I can ask it to come up with more copy options for my flavours or I could add some specific things I do or don't want:
Conclusion
This example shows how a well-crafted Custom Agent - grounded in your brand’s tone, values, and creative library, can support a marketing team by turning simple flavour names into evocative, short-form copy and imaginative campaign ideas.
That said, this version is just a starting point. You might choose to refine your Custom Agent further by adding tone presets for different campaign styles (e.g. playful, nostalgic, elegant), tailoring the structure of the copy by channel (e.g. headline only vs. full body text), or prompting the agent to suggest CTA phrasing, hashtags, or pairings for each flavour. You could even expand it to generate flavour ideas from trend data or customer insights.