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Should You Build an Agent? A Practical Guide for Anyone Curious About Building Effective AI Agents

InvestGlass Smart Agent Prompt

So, you’ve been hearing all the buzz about AI agents and wondering: “Should I build an agent for my work, or am I better off sticking to simpler workflows?”

If you’re anything like most developers, teams, and curious users dabbling in AI, you’ve probably already seen agent builder tools, read a bit of documentation, and maybe even tried to create your first AI agent. But here’s the thing: building AI agents isn’t just about throwing in a large language model, adding a few tool definitions, and calling it a day. Building agents involves a broader process of designing, integrating, and deploying modular AI components, often using the right framework to ensure smooth integration and scalability across different environments.

You need to understand when it’s worth it to build agents, what core principles make them work well—like how agents manage context to interact dynamically with tools and data—and why so many fail in production. Let’s break it down casually and practically—without the hype.

Why AI Agents Are a Big Deal (But Not Always the Right Answer)

AI agents are essentially systems powered by a large language model (LLM) that can interact with tools, access data, execute intermediate steps, and respond intelligently to input. They feel almost human in the way they follow instructions, manage conversation flow, and enable many applications. These agents have the capability to integrate with external tools, access specialized data, and perform complex tasks that set them apart from simpler automation solutions.

Imagine:

  • Asking an agent for current weather information in London, and it fetches data through an API key, accesses knowledge from external sources, formats it neatly, and even writes it to a text file in your working directory.
  • Creating an agent that helps your customers by reading local files, analysing details, and providing accurate answers automatically.

Sounds brilliant, right? And indeed, it is—for complex tasks. But if you just want to automate simple jobs (like moving a file or sending standard messages), AI agents can be overkill. Workflows or other tools will do the trick far faster.

When deploying agents, it’s important to define system boundaries and requirements to ensure secure and reliable operation.

The Checklist: When Should You Build Agents?

When developers and teams ask me how to determine whether they should start building AI agents, I often share this practical checklist. Think of it as a casual set of rules you can apply while sipping your morning tea. However, it’s important to consider every detail of your use case and requirements to ensure you make an informed decision.

Note: Be careful not to overlook specific constraints or integration challenges—missing these details is a common pitfall when deciding to build agents.

1. Is the task complex enough?

If you’re dealing with straightforward tasks (e.g., “send email X to team Y”), don’t over-engineer. But for multi-step processes that require reasoning—like analysing customer feedback from multiple locations, where understanding and integrating location data is crucial for accurate insights, and automatically drafting reports—an agent can shine.

2. Is it valuable enough to justify?

If you build an agent for something trivial, you’re wasting tokens and effort. Focus on tasks tied to real value, such as automating parts of sales processes, answering customer queries, or integrating local development tools into enterprise systems. Consider integrating with cloud-based platforms or services to enhance scalability and accessibility.

3. Can all parts of the task be automated?

Check if the tools, APIs, or files you need are accessible. Agents are created within the system, and the platform automatically creates the necessary resources, such as data stores and tool configurations, to enable automation. Agents don’t do magic. If you lack access to key data or systems, either reduce scope or use hybrid approaches (e.g., human-in-the-loop).

4. What’s the cost of errors?

High-stakes scenarios (e.g., medical or finance systems) demand appropriate guardrails. You might keep agents read-only at first, testing their behaviour in a controlled way before handing them the keys to tool execution.


Your First AI Agent: What to Expect

Let’s say you’re ready to create your first AI agent. Here’s a simple example using Python and an agent builder library:

from my_agent_library import Agent, Tools
import os

api_key = os.getenv("OPENAI_API_KEY")

tools = Tools([
    {"name": "weather_tool", "description": "Fetch current weather info. The description field provides detailed descriptions to guide the agent's use of the tool.", "execute": fetch_weather}
])

agent = Agent(
    model="gpt-4",
    api_key=api_key,
    tools=tools,
    working_directory="./agents",
    default="respond with details clearly"
)

agent.create("Get the current weather in London and save it as a text file.")

This code snippet sets up an agent with tool execution enabled and defines instructions for fetching weather information and saving it locally. The description field in the tool definition offers detailed descriptions to help the agent understand and use the tool correctly. You can issue the following command to the agent to perform a specific task, such as creating a file or running a script.

It’s minimal, but it captures the core principles: define tools, import your libraries, add instructions, and let the agent interact with systems. The agent processes each message in the conversation to generate appropriate responses and actions.

Building Effective Agents: From Simple to Complex

When building effective agents, think of it like levelling up in stages. Start small, then gradually expand. Well-crafted prompts are essential for effective tool interactions, as they guide the agent to produce accurate and relevant outputs.

  1. Start with basic tasks – Create a new agent to search your local files, answer questions about data in a text file, or import notes from customers and respond.
  2. Move to tool execution – Enable tools that interact with APIs, such as fetching weather or searching customer locations.
  3. Handle intermediate steps – Let your agent plan: break tasks down, process inputs step by step, ground responses in reliable data sources, and communicate results clearly.
  4. Integrate with other tools – Expand your agent’s capabilities by linking it to CRMs, project management systems, or messaging apps to answer questions or send updates automatically.

The growing ecosystem of agent builder frameworks makes this easier than ever—even if you’re new to programming languages.

No-Code and Low-Code Agent Builders

Good news: you don’t need to be a hardcore programmer to start building AI agents. Many modern agent builders allow you to create agents without writing much code at all.

For example:

  • Drag and drop a prompt, add a description of what your agent should do, connect an API key, and hit the “create” button.
  • Start a new conversation with your agent by simply typing “get the current weather in Paris” and watch it fetch the data and answer instantly.

Even if you prefer a more hands-on approach, these tools often generate the code snippet for you automatically, which is great for learning.

Common Mistakes: Why Most AI Agents Fail in Production

Here’s where developers, even experienced ones, trip up:

  • Forgetting appropriate guardrails: Agents without constraints may access tools or files they shouldn’t.
  • Not testing thoroughly: Skipping test runs on intermediate steps means you won’t catch bugs until customers do.
  • Poor prompt design: Without clear instructions and enough tokens for reasoning, agents get stuck or hallucinate.
  • Lack of observability: If you can’t see logs, messages, or data flows, debugging is nearly impossible.

Tip: Always set up a default working directory for local development, keep sensitive API keys safe, and log every command your agent executes.

Building AI Agents Without Coding: Yes, You Can!

You don’t need to know complex programming languages to build agents anymore. No-code platforms let you:

  • Upload a file or connect to local files.
  • Describe (in plain English) the tasks you want the agent to enable.
  • Provide a prompt or content string like: “Search my notes and answer questions from customers.”
  • Test the agent right away by starting a new conversation.

These platforms handle the heavy lifting of tool definitions, intermediate steps, and LLM reasoning.

The Role of Developers and Teams

While no-code tools lower the barrier, developers still play a crucial role. They:

  • Import libraries and other tools to extend agents.
  • Write tool execution scripts and connect APIs.
  • Test agents rigorously with various input scenarios.
  • Document systems, code snippets, and capabilities so users can replicate success.

Good documentation and clear instructions ensure that teams and customers can interact with agents smoothly.

Growing Ecosystem of Tools

The AI agent space has exploded into a growing ecosystem of tools. Whether you’re tinkering locally or deploying to production for enterprise customers, you now have many applications to choose from:

  • Agent builders with visual interfaces.
  • Pre-configured agents that respond to specific tasks (like searching local files or fetching weather info).
  • Libraries that integrate with programming languages and frameworks developers already use.

Real-World Applications of AI Agents

AI agents are making a real impact across a wide range of industries, transforming how organizations and users tackle complex tasks. In customer service, for example, AI-powered agents can answer questions around the clock, helping users resolve issues and access information instantly—no more waiting on hold. Healthcare systems are leveraging effective agents to analyze patient data, assist with medical diagnoses, and even create personalized treatment plans, all while handling sensitive information with care.

Finance teams use AI agents to detect fraudulent transactions, predict market trends, and provide tailored investment advice, automating tasks that once required hours of manual analysis. In education, agents can create personalized learning experiences, grade assignments, and deliver real-time feedback to students, making learning more adaptive and engaging.

What makes these agents so powerful is their ability to break down complex tasks into manageable steps, interact with various data sources, and deliver actionable answers. Frameworks and agent builder tools make it easier than ever to create and deploy these systems, allowing developers and teams to focus on building effective agents that meet real-world needs. Of course, it’s important to balance performance, cost, and latency—especially as agents take on more demanding roles in critical systems. By thoughtfully applying AI agents to the right problems, organizations can unlock new efficiencies and deliver better experiences for users everywhere.

Measuring Agent Performance

Building effective agents isn’t just about getting them up and running—it’s about making sure they actually deliver value. To do that, you need to measure how well your AI agent is performing. Start by tracking key performance indicators (KPIs) like accuracy, response time, user satisfaction, and how often the agent successfully completes its assigned tasks. Metrics such as precision, recall, and F1-score can help you dig deeper into how reliably your agent answers questions and handles user requests.

User feedback is another goldmine for improvement. By collecting and analyzing feedback, you can spot patterns, identify pain points, and refine your agent’s behavior. Regular testing—both automated and with real users—ensures your agent is ready for real-world scenarios and can handle unexpected inputs gracefully.

Agent builder tools and frameworks like LangChain and Vertex AI Agent Builder make it easier to monitor, test, and optimize your agents. They provide built-in analytics and testing environments, so developers can focus on building effective agents that keep getting better over time. Remember, building AI agents is an iterative process: measure, learn, and improve to ensure your agent continues to meet user needs and deliver reliable results.

Agent Security and Reliability

When it comes to deploying AI agents in the real world, security and reliability are non-negotiable—especially in sensitive fields like healthcare and finance. To build trustworthy agents, developers must implement appropriate guardrails at every stage. This means validating all user input, handling errors gracefully, and ensuring that data is stored and processed securely. Transparent decision-making is also key: users should be able to understand how the agent arrives at its answers, which helps build confidence and trust.

Regular testing and auditing are essential to catch vulnerabilities before they become problems. By using established frameworks and agent builder tools, such as Vertex AI Agent Builder, developers can leverage built-in security features and best practices, making it easier to create robust, reliable agents. These tools often include support for secure data handling, input validation, and detailed logging, so you can monitor your agent’s behavior and quickly address any issues.

Ultimately, creating secure and reliable AI agents is about more than just technology—it’s about building systems that users can depend on. By prioritizing security, transparency, and ongoing testing, developers can create agents that not only perform well but also earn the trust of users and stakeholders.

Final Thoughts: Build Agents Thoughtfully

The decision to build an agent shouldn’t be rushed. Ask yourself:

  • Is this a complex task that truly benefits from AI?
  • Do I have the data, access, and tools needed?
  • Are the appropriate guardrails in place?

If yes, go ahead and build an agent. If not, you might be better off sticking with simpler workflows or using existing tools. Remember: building effective agents is less about flashy demos and more about designing robust systems that actually help customers, teams, and users.

FAQs: Answering Common Questions

1. What are the 4 rules of AI agents?

  • Complexity: Only build agents for complex tasks that need reasoning.
  • Value: Ensure the task is worth automating.
  • Feasibility: Check if the tools, APIs, and data are available.
  • Risk: Use appropriate guardrails for high-stakes environments.

2. Why do we use agents?

Because they enable automation of tasks that workflows can’t handle. They interact with data, answer questions, communicate with customers, and respond intelligently—freeing teams and developers to focus on bigger priorities.

3. Can I build AI agents without coding?

Absolutely. Modern platforms let you create agents, connect APIs, and even test capabilities with a simple description or prompt. Just log in, set up a new account, paste in your API key, and create a new agent without touching code.

4. Why do most AI agents fail in production and how to build ones that don’t?

Most fail because they lack testing, observability, and guardrails. To succeed:

  • Start with small examples.
  • Test intermediate steps and monitor conversation flow.
  • Provide enough tokens for reasoning.
  • Keep instructions clear, enable only necessary tools, and respond to feedback from users.

Follow these core principles, and you’ll be building effective agents that actually work—whether they’re reading a text file, answering customer messages, or fetching weather information for a new conversation.

artificial intelligence