The Core Components of Any Real AI Agent
Forget the hype. An AI agent is just a loop. A simple, repeatable process that allows a Large Language Model (LLM) to interact with the real world. It’s not magic, it’s plumbing. If you understand the pipes, you can build one.
Every functional agent has four parts:
- A Goal (or Trigger): This is the starting pistol. It’s the “why” for the agent’s existence. A new email lands in an inbox, a new row is added to a Google Sheet, a payment fails in Stripe. It’s a specific event that kicks off the workflow. Without a clear trigger, you just have a chatbot waiting for instructions.
- A Brain (The LLM): This is the decision-making core. You send it information, and it tells you what to do next. For this, you’ll use an API from a provider like OpenAI, Anthropic, or Google. The key isn’t just asking it questions; it’s giving it structured information and demanding a structured response.
- Tools (The Hands and Eyes): This is the most critical piece. An LLM by itself is just a brain in a jar. It can’t do anything. Tools are what connect it to the world. A tool can be a web search API, the ability to send an email, a function that checks your CRM, or a connection to your product database. An agent without tools is useless.
- State (The Memory): How does the agent know what it just did? How does it remember the results of the last step? This is its short-term memory, or “state.” In no-code tools, this is often just the data passed from one step to the next. For more complex agents, it might be a dedicated database or even a simple text file.
That’s it. Goal -> Brain -> Tools -> State -> back to Brain. Anyone who tells you it’s more complicated than that is probably trying to sell you something overpriced.
What Most Guides on How to Create AI Agents Get Wrong
The biggest mistake I see is the “one giant prompt” fallacy. People try to build a single, monolithic agent with a 2,000-word prompt that instructs it to do everything from research to analysis to writing to sending an email. This always fails.
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It’s a black box. When it breaks (and it will), you have no idea which part of the instruction it misunderstood. It’s also incredibly expensive, as you’re sending a massive context window to the LLM for every single decision.
Honestly, any guide telling you to build a single-prompt “god agent” has never run one in production. It’s a recipe for expensive, unpredictable garbage.
The correct approach is modular. You build a chain of smaller, specialized agents (or steps). Think of it like an assembly line:
- Step 1: The Researcher. Its only job is to take a query (like a company domain) and use a search tool to find relevant information. Its output is just raw text.
- Step 2: The Analyst. Its only job is to take the raw text from the Researcher and extract specific, structured data. Does this company have more than 50 employees? What industry are they in? Its output is clean JSON.
- Step 3: The Writer. It takes the structured JSON from the Analyst and, if the criteria are met, drafts a personalized email.
Each step is a separate, simple prompt. It’s cheaper, faster, and a thousand times easier to debug. If the final email is bad, you can check the output of the Analyst. If the Analyst’s data is wrong, you can check the output of the Researcher. You have visibility. You have control.
A Practical Build: The No-Code Lead Qualification Agent
Let’s build that lead qualification agent I mentioned. We’ll use a no-code stack that costs less than a fancy dinner.
The Stack:
- Orchestrator: the Make platform. This is the glue that holds everything together. It provides the visual interface for building the workflow. The Pro plan at $29/mo is the real entry point for running multiple agents reliably. I think it’s fairly priced for what you get.
- Eyes: Brave Search API. For web research. It’s affordable and provides solid, ad-free search results, which is exactly what an agent needs. My main gripe is with their API documentation, which is… let’s call it ‘minimalist’. You’ll burn an hour figuring out the correct request format for something that should be a simple copy-paste.
- Brain: Claude 3 Opus via Anthropic’s API. I find Opus follows complex instructions for JSON formatting more reliably than GPT-4, which is critical for automation.
Here’s the step-by-step operator playbook:
- The Trigger: Create a new scenario in Make.com with the “Watch New Rows” module for Google Sheets. Point it to a sheet where you list new leads with a company name and domain.
- The Research Step: Add an “HTTP – Make a request” module. Connect it to the Brave Search API. You’ll pass the company domain from the Google Sheet into a search query like
"[Company Name]" funding OR "[Company Name]" about us. This gives the agent some context to work with. - The Analysis Step: Add an “Anthropic – Create a Completion” module. This is where the magic happens. You’ll feed the search results from Brave into a prompt. This prompt doesn’t ask for an email; it asks for a decision.
Your prompt should look something like this:
You are an expert B2B lead analyst. Your job is to determine if a company is a good fit based on the provided web search context. Our Ideal Customer Profile is: B2B SaaS companies, located in North America, with 50-500 employees.
Based on the following text, determine if the company fits our criteria.
Context: {{search_results_from_brave}}
Your response MUST be a valid JSON object with the following schema: { "is_qualified": boolean, "reasoning": "string (explain your decision in one sentence)", "employee_count_estimate": integer }
This is the entire game.
By forcing the LLM to return structured JSON, you turn an unpredictable language model into a predictable automation component. Make.com can then parse this JSON output easily.
- The Routing Step: Add a “Router” module in Make.com. This creates a fork in the road. Set up a filter on one path that only continues if the
is_qualifiedvalue from the previous step istrue. - The Writing Step: On the “true” path, add another Anthropic module. This one’s prompt is for writing:
You are a friendly sales development rep. Based on this data: {{json_from_analyst}}, write a short, personalized, 3-sentence email to the CEO of the company. Do not use buzzwords. End with a question. - The Final Step: Add a “Google Sheets – Update a Row” module. Write the agent’s decision (`is_qualified`, `reasoning`) and the drafted email back to the original sheet for a human to review and send.
You now have a working AI agent that automates a task that would take a human 15 minutes per lead, and it does it in about 45 seconds.
