🤖Build Your First AI Agent

Most people never build an agent because they start with the tool. Start with the job. There’s only one thing to decide first: what do you want your agent to do?

• Research a topic
• Write emails
• Review resumes
• Come up with content ideas
• Summarize documents
• Write product copy
• Plan study sessions

Pick one. Everything below is filling in the blanks for that one job.

Step 1: Create a new agent

Go to crewai.com and sign up for the free plan.

Then open Agents Repository → Create New Agent. You’ll see these fields:

• Role
• Goal
• Backstory
• Tools
• Capabilities
• Integration Apps
• MCP Servers

Here’s what each one means, and exactly what to put in it.

Step 2: Give it a role

The role answers one question: who is this agent?

[TYPE OF AGENT]

For example: AI Content Researcher, Email Copywriter, Resume Reviewer, Study Planner, Customer Support Agent. Keep it simple — a job title, not a sentence.

Step 3: Give it a goal

The goal answers: what should this agent actually achieve? Copy this and fill in the brackets:

Your goal is to help the user [MAIN JOB].
You should [WHAT IT SHOULD DO].
The final result should be [DESIRED RESULT].
Keep the output [STYLE / QUALITY REQUIREMENTS].

Example — an email agent:

Your goal is to help the user create better marketing emails.
You should understand what they’re selling, who the audience is and what they want the reader to do.
The final result should be a clear, persuasive email.
Keep the output short, simple and natural.

Swap in your own use case.

Step 4: Write the backstory

The backstory tells CrewAI how this agent should think and work. It’s the field most people rush, and it’s where the quality comes from. Copy this template:

You are an experienced [ROLE].
You specialize in [AREA OF EXPERTISE].

Before starting a task, understand:

• [THING 1]
• [THING 2]
• [THING 3]

When working:

• [RULE 1]
• [RULE 2]
• [RULE 3]
• [RULE 4]

Avoid:

• [THING TO AVOID]
• [THING TO AVOID]
• [THING TO AVOID]

Never invent information the user hasn’t provided.
If something is unclear or missing, work only with the information available unless you need to ask.

Example — a resume reviewer:

You are an experienced resume reviewer.
You specialize in helping people make their resumes clearer and more relevant to the jobs they want.

Before reviewing a resume, understand:

• the person’s experience
• the role they’re applying for
• the skills the job requires

When working:

• be specific
• point out weak sections
• suggest better wording
• keep advice easy to understand

Avoid:

• vague advice
• unnecessary jargon
• inventing experience or achievements

Never invent information the user hasn’t provided.

Step 5: Tools — probably none yet

Tools give your agent extra abilities. It doesn’t need any of them to think, write, summarize, classify, rewrite, or turn one format into another.

So for your first agent, leave Tools empty. Add one only when the job actually needs it:

• Needs current information? Add a web search tool.
• Needs to read webpages? Add a website reading or scraping tool.
• Needs to work with files? Add a file tool.
• Needs to take some other action? Find the tool built for that job.

Some tools need their own API keys — one more reason to start without them.

Step 6: Set capabilities

For a first agent, start here:

You can change any of these later.

Step 7: Integration apps — leave empty

Integrations connect your agent to other apps: read data from one app, do something with it, send the result somewhere else. If your first agent only works with what you paste in, leave Integrations empty.

Step 8: MCP servers — leave empty

MCP servers are another way to give your agent access to outside tools, apps and data. You don’t need them for a first agent. Leave it empty for now.

Step 9: Create the agent

Click Create Agent. Your agent now knows who it is, what it should do and how it should work.

What it doesn’t have yet is a job. That’s next.

Step 10: Give it a job — create a crew

Go to Crew Studio → Create New Crew and find the box that says Describe your automation. Paste this and fill in the brackets:

Create a simple workflow using my EXISTING agent from the Agents Repository called “[AGENT NAME]”.
Do not create another agent.
Ask me for one plain text input called “[INPUT NAME]”.
The user should be able to paste the information directly into a text box.
Pass this input to my “[AGENT NAME]” agent.
Give the agent this task:
[DESCRIBE EXACTLY WHAT YOU WANT THE AGENT TO DO]

The final output should contain:

1. [OUTPUT 1]
2. [OUTPUT 2]
3. [OUTPUT 3]
4. [OUTPUT 4]

Follow these rules:

• [RULE 1]
• [RULE 2]
• [RULE 3]

Return the finished result as the final output.

Example: the resume reviewer

If your agent is called Resume Reviewer, the Crew Studio prompt becomes:

Create a simple workflow using my EXISTING agent from the Agents Repository called “Resume Reviewer”.
Do not create another agent.
Ask me for one plain text input called “resume”.
The user should be able to paste their resume directly into a text box.
Do not require a file upload.
Pass this input to my Resume Reviewer agent.
Give the agent this task:
Review the resume and find the biggest things that could be improved.

The final output should contain:

1. Overall score out of 10
2. Biggest problems
3. Sections that should be rewritten
4. Specific suggestions
5. A better version of the weakest section

Follow these rules:

• Keep advice specific
• Use simple English
• Do not invent experience
• Do not change factual information

Return the finished review as the final output.

The same template works for almost any agent — change the name, the input and the task.

Step 11: Writing the task by hand instead

If you’d rather set the task up yourself, this goes in Task Description:

You have been given the following input:
{[INPUT_NAME]}

Your task is to:
[MAIN TASK]

Before producing the final answer:

1. [STEP 1]
2. [STEP 2]
3. [STEP 3]

Return:

• [OUTPUT 1]
• [OUTPUT 2]
• [OUTPUT 3]

Follow these rules:

• [RULE 1]
• [RULE 2]
• [RULE 3]

Do not invent information that was not provided.

And this goes in Expected Output:

A completed [TYPE OF OUTPUT] containing:

1. [SECTION 1]
2. [SECTION 2]
3. [SECTION 3]
4. [SECTION 4]

The result should be clear, specific and ready to use.

Step 12: Test it

Hit Run and give it some sample input:

The formula to remember

Seven questions, in this order. Answer them and you’ve built an agent.

📋 The master template

Fill this out before you open CrewAI. Once it’s done, every field above is already written.

I want to create an AI agent.

Agent name: [NAME]
Role: [WHO THE AGENT IS]
Main job: [WHAT IT SHOULD DO]
Input it will receive: [WHAT YOU WILL GIVE IT]
Output I want: [WHAT IT SHOULD RETURN]
How it should work: [YOUR RULES]
Things it should avoid: [THINGS TO AVOID]

Does it need current information from the internet? [YES / NO]
Does it need to access another app? [YES / NO]
Does it need to read files or websites? [YES / NO]

Stuck on the brackets? Paste the template into ChatGPT or Claude with one line about the job you want done, and let it fill in the rest.