January 28, 2026

Why you need custom AI agents, not just better chats

Invest the time in tools that are repeatable, shareable, and scalable.
MarTech
TABLE OF CONTENTS

We're all guilty of falling into lazy habits out of sheer inertia. It’s Monday morning and you’re staring at a blinking cursor of ChatGPT, pasting in the same three paragraphs of background context, and hoping the AI "gets it" this time. It’s manual, mind-numbingly repetitive, and frankly, very 2024.

Spoiler alert: There’s a better way to work.

AI agents vs LLM chats

If you’re a modern marketer, you’ve heard the buzz around agentic AI. The topic was on everyone’s lips at CES 2026, and it’s inescapable on LinkedIn. 

As with the term “AI” itself, there’s a range of opinion and definition as to what “agentic AI” even means. 

For those in the experimentation phase of AI-driven martech, the thought of constructing agents that are able to reason and take action on their own can be daunting or implausible. But even at their most basic—riding the hazy line between AI assistants and proper AI agents—there are many reasons to explore an agentic platform rather than cobbling together one-off tasks in an LLM chat.

Here’s why moving from “prompting" to "building" is the upgrade your team didn’t know it needed—and how Agent Cloud can help get you there.

How to tell your agent what to do

When you open a standard LLM chat, you’re essentially starting from scratch. The AI may remember threads of previous conversations, but it might do so haphazardly. In each new chat session, you might feel like you’re re-introducing yourself, explaining the rules, adding some guardrails, and hoping for the best.

Building a custom agent in a platform like Agent Cloud allows you to architect the tool once and use it forever. It comes down to three simple but powerful levers:

  1. The directive layer (your agent’s “personality”): Instead of a fleeting prompt, you feed the agent a permanent set of instructions. This is the agent's DNA. It defines who they are (e.g., "You are a cynical senior copywriter who hates jargon"), how they format output, and what they know about your company.
  2. The model selection (the “engine” beneath the hood): Different tasks require different horsepower. Agent Cloud lets you swap the underlying "brain" of your agent, from Gemini to Claude to ChatGPT and beyond. Need creative flair? Build your agent on one model. Need heavy data reasoning? Rebuild it on another with a single click.
  3. The institutional knowledge (your agent’s inside intel): Curate knowledge bases that your custom agent can connect to, uploading foundational documents like brand guidelines.

The benefits of a custom agent

Why build an agent? Because consistency is key when you’re using AI at scale.

  • Immunity to "prompt drift": In long chat threads, LLMs often "forget" their original instructions. A custom agent’s directions are hard-coded into every interaction, ensuring the 100th output is as sharp as the first.
  • Standardized excellence: If five different employees use a standard LLM, you get five different results. If they all use the same "Q3 Report Agent" in Agent Cloud, you get a unified, brand-safe output every time.
  • Less risk of "AI sycophancy": For a variety of reasons, LLMs are trained to please their human interrogators. This can lead to a "yes man" phenomena that isn't great for sharpening your marketing concepts. Building a custom agent lets you code in guardrails to curb this problem.
  • Zero "onboarding" time: Your custom agent already knows your style guide, your banned words, and your formatting quirks. You skip the 15-minute setup (or hunting for brand assets on your shared server) and go straight to the work.

Ready to stop repeating yourself?

We’d love to walk you through how custom agent creation works in Agent Cloud.

Think of it as graduating from casual chatting to professional engineering, but with an interface that’s intuitive enough for the layman. When you hardwire your best, most thorough directions into an agent, you aren't just avoiding the frustration of having to explain yourself multiple times to a confused LLM. 

Instead, you’re spending a bit of time up front in order to build a tool that acts like a micro-focused co-worker. Share it with your team, scale your output, and leave the days of haphazard LLM chat behind.

Scott Indrisek

Scott Indrisek is the Senior Editorial Lead at The Marketing Cloud

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