AI Strategy

What Is an AI Agent? A Plain English Explanation

AI agents are everywhere in the news, but most explanations are either too vague or too technical. Here's a practical breakdown of what AI agents are, how they work, and when you should use one.

Squirrel AI·

The One-Sentence Definition

An AI agent is a software system that uses an AI model to perceive information, make decisions, and take actions in the real world — repeatedly, until it achieves a goal.

That's it. The "agent" part is about autonomy and action-taking. The "AI" part is about using a language model (like Claude or GPT-4.5) for the reasoning.

How AI Agents Differ from Chatbots

A chatbot responds to messages. You ask it a question, it answers. The conversation goes back and forth. It doesn't do anything in your systems.

An AI agent can take actions. It can:

  • Read your emails and decide which ones need urgent replies
  • Search the web for information and synthesise what it finds
  • Query your database and generate a report
  • Send messages on your behalf
  • Update records in your CRM
  • Make API calls to external services

The difference is real-world impact. A chatbot tells you what to do. An agent does it.

How Agents Actually Work

Under the hood, most AI agents follow a loop:

  1. Perceive — receive input (a message, a scheduled trigger, a webhook)
  2. Think — pass the input to an AI model along with available tools and context
  3. Act — the AI decides which tool to use and calls it
  4. Observe — receive the result of the tool call
  5. Repeat — go back to step 2 with the new information, until the goal is achieved

This loop is what makes agents powerful. A single model call can only do so much — a multi-step agent can research a topic, write a summary, format it as a report, and send it via email, all triggered by a single instruction.

Real Examples We've Built

Customer Support Agent

  • Receives a customer support ticket
  • Checks order history and status in the e-commerce platform
  • Decides if it can resolve automatically (refund, reship, update)
  • Takes the action, or routes to a human with full context pre-written

Deal Origination Agent

  • Receives a batch of company profiles
  • For each company, researches the web for revenue, sector, and recent news
  • Scores the opportunity against the fund's investment criteria
  • Outputs a prioritised list with rationale

Lead Research Agent

  • Takes a list of target companies
  • Searches for decision-makers, LinkedIn profiles, recent company news
  • Drafts personalised outreach emails for each contact
  • Saves to CRM and queues for sending

The Tools an Agent Can Use

An agent is only as good as the tools available to it. Common tools include:

  • Web search — real-time information retrieval
  • Database queries — read/write to SQL or NoSQL databases
  • API calls — connect to any external service (CRM, email, Slack, Stripe)
  • File operations — read, write, or parse documents
  • Code execution — run Python or JavaScript for calculations
  • Memory — store and retrieve information across sessions

The art of building good agents is picking the right set of tools and writing clear instructions for when to use each one.

When Should You Use an AI Agent?

Use an agent when:

  • The task requires multiple steps with decisions at each step
  • The outcome depends on real-world information that changes (not static knowledge)
  • You want the AI to take actions, not just produce text
  • The task is repetitive — running the same multi-step process thousands of times

Don't use an agent when:

  • A simple automation (rule-based, deterministic) will do — agents add complexity and cost
  • Accuracy requirements are very high and errors are costly — agents can make mistakes
  • The task is truly one-shot (ask a question, get an answer)

The State of Agents in 2026

Agents have gone from research project to production reality in the past 18 months. The main enablers:

  • Better reasoning models — Claude Sonnet 4.5, GPT-4.5, Gemini 2.5 can follow complex instructions reliably
  • Tool calling APIs — model providers now expose clean APIs for structured tool use
  • Better infrastructure — platforms like n8n make it practical to deploy agent workflows without deep engineering

We're now deploying agents that handle thousands of tasks per day with minimal human oversight. The reliability is good enough for many business processes.

The next 12 months will see agents move from "impressive demos" to "standard infrastructure." The businesses that deploy them now will have a significant operational advantage.


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