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Best PracticesNovember 10, 20265 min read

Custom AI Agents: How to Design, Configure and Govern Them

By · AI agents for European teams

The team behind AgentWorks, the AI workspace for European organisations.

Reviewed November 10, 2026

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Custom AI Agents: How to Design, Configure and Govern Them

Operations lead configuring a custom AI agent

A custom AI agent is an AI system set up around your own processes, data, tools and permissions, so it can complete a recurring piece of work rather than just answer questions. You don't need to code to build one. Most teams start from a template, connect the tools the work already runs in, write clear instructions, and keep a human approving anything that sends, books or changes data. This guide covers each of those steps, plus testing and GDPR.

TL;DR

  • A custom agent has a goal, instructions, tools, knowledge and permissions. A chatbot only replies to messages.
  • The best first candidates are recurring, rule-bound tasks with clear inputs: inbox triage, reply drafting, meeting notes to tasks, order emails.
  • Templates give you a tested starting structure. You adapt the instructions, data sources and approval rules to your business.
  • Roll out in stages: sandbox, shadow mode, then limited live use with approvals and logs switched on.
  • For EU personal data, define roles, minimise access, keep records and add human oversight before you scale.

Table of Contents

What custom AI agents are, and how they differ from chatbots

A chatbot receives a message and sends a response. An agent is given a goal, can call tools, read the results and decide what to do next, repeating the loop without needing a prompt at every step. The same source places chatbots at the reactive end of a continuum: no tool calls and no persistent memory beyond the conversation.

The word "custom" adds a second distinction. A prebuilt, general-purpose assistant knows nothing about your pricing rules, your supplier list or your tone of voice. A custom agent is configured with exactly those things. In practice that means five components:

  1. A defined job. One outcome, such as "draft replies to order-status emails".
  2. Instructions. How the agent should behave, what it must never do, and what good output looks like.
  3. Tools and integrations. Access to Outlook, Shopify, Google Drive or whichever systems hold the work.
  4. Knowledge. Documents, policies and past examples the agent can draw on.
  5. Permissions and approvals. What it may read, what it may change, and which actions need a person to sign off.

Most failed agent projects get one of these wrong, usually the first. An agent with a vague job produces vague output.

Which tasks suit a custom agent

An agent earns its place where work is repetitive, text-heavy, spread across several tools and governed by rules a new colleague could learn in a week. If you could write the procedure on one page, an agent can probably run it.

Strong candidates:

  • Shared inbox handling. Sorting, labelling and routing incoming mail, then drafting replies for review. See how an inbox that sorts itself works in practice.
  • Meeting follow-up. Turning notes into assigned tasks, as in meeting notes to tasks.
  • Order and customer emails. Answering where-is-my-order and returns questions from shop data, which is the focus of our e-commerce workflows.
  • Complaints, quotes and supplier correspondence in manufacturing, where an audit trail matters as much as speed.
  • Reporting and monitoring that pulls figures from several systems on a schedule. For technical teams, IT operations is a common area.

Weaker candidates are tasks with no clear definition of done, tasks that depend on judgement nobody has written down, and anything where a wrong action cannot be reversed and nobody reviews it. For those, keep the agent in a drafting role and let a person decide.

Agent templates explained

An agent template is a pre-built configuration for a common job. It bundles the instructions, expected inputs, output format, suggested tools and sensible default guardrails, so you adapt a working structure instead of writing everything from a blank page.

A good template saves time in three places:

  • Instruction design. The hardest part of an agent is stating the job precisely. A template already has a tested structure: role, steps, constraints, output format.
  • Integration choices. It names the tools the task normally touches, so you connect those and nothing else.
  • Safe defaults. Approval steps are placed where the agent sends, books or changes something.

Our own examples include the Email Triage Assistant and the Inbox Reply Drafter. Both are written for personal productivity use but show the pattern: a narrow job, clear inputs, a draft or label as output.

How to adapt a template

  1. Rewrite the goal in your terms. Replace generic wording with your product names, service levels and escalation rules.
  2. Add your knowledge. Attach the policies, price lists, FAQs and example replies the agent should rely on.
  3. Tighten the tools. Remove integrations the job doesn't need. Fewer connections mean a smaller risk surface.
  4. Set the approval rules. Decide which actions are automatic and which wait for a person.
  5. Run it on real past cases before it touches anything live.

Sector-specific templates go one step further, because they carry the vocabulary and documentation habits of the field, such as quality records in manufacturing or order data in retail.

How to build an AI agent for your business, and whether you need code

You can build a working business agent without writing code. Code-based builds, using frameworks and APIs, make sense when you need unusual logic or deep integration into proprietary systems. For a recurring workflow in email, documents and a shop or CRM, a configurable workspace is faster and easier for the process owner to maintain, which matters because the person who understands the work should be the one adjusting it.

A practical build sequence:

  1. Pick one workflow. Choose the task with the highest volume and the clearest rules. Nail the first workflow before adding a second.
  2. Write the definition of done. For example: "Every order-status email gets a draft reply with the correct tracking link within minutes, and a person approves it."
  3. Start from a template close to that job.
  4. Connect tools and knowledge.
  5. Set permissions and approvals.
  6. Test, then release gradually.
  7. Review the logs weekly and refine instructions from the real failures you see.

Configuring instructions, tools, data access and permissions

Instructions

Write them like a handover note to a capable new colleague. State the goal, the steps in order, the tone, what to do when information is missing, and what the agent must never do. Include two or three examples of good output. Avoid long lists of rules that contradict each other.

Tools

Grant each integration the narrowest scope that does the job. A reply-drafting agent needs to read mail and create drafts. It does not need permission to delete messages or read the whole drive.

Specialist reviewing an email reply draft

Data and knowledge

Connect a defined knowledge base rather than "everything". Curated sources produce more consistent answers, and they make it easier to explain later where an answer came from.

Models

Different tasks suit different models. AgentWorks supports Claude, GPT, Gemini and Mistral, so a team can match the model to the task and its data requirements rather than rebuilding the workflow.

Permissions and approvals

Separate reading from acting. Reading is lower risk. Sending, booking and changing records are where errors become visible to customers, so put an approval step there. In AgentWorks, human approval controls apply to any agent action that sends, books or changes data.

Managing multiple agents

Once a second and third agent exist, the problem shifts from building to governing. Keep it simple:

  • One owner per agent. A named person is responsible for its instructions and results.
  • Version your instructions. Record what changed and why, so a drop in quality can be traced to an edit.
  • Use consistent naming and scopes. An agent's name should say its job, and its permissions should match.
  • Review usage and cost together. Per-run pricing makes it easy to see which agents earn their keep.
  • Centralise logs. One place to see what every agent did makes review realistic. Our guide to agent observability covers logs, traces and evaluations.

Testing, deploying and monitoring

Safe rollout is progressive, not a switch. Teradata's AgentOps guidance recommends sandbox validation, golden tasks, shadow mode, canary testing and gradual exposure, along with traces, audit trails and a documented way to roll back or freeze an agent. Applied to a small team, that becomes:

StageWhat happensPass condition
SandboxAgent runs on past, anonymised casesOutputs match your golden examples
ShadowAgent drafts alongside people, nothing is sentDrafts are at least as good as human replies on a sample
Limited liveOne mailbox or one customer segment, approvals onNo unapproved actions, few corrections
Full liveWider scope, sampled review continuesError rate stays within your threshold

Build your golden set from real cases: a dozen typical ones and a handful of awkward ones, such as an angry customer, a missing order number or an ambiguous request. Re-run the set every time you change instructions, tools or the model.

GDPR and the EU AI Act: configure for compliance from day one

If an agent touches personal data of people in the EU, the configuration choices are compliance choices. The Spanish data protection authority's guidance on agentic AI sets out what to consider: identify the lawful basis and the controller and processor roles, give clear notices, minimise data and permissions, support data subject rights, assess transfers outside the EU/EEA, and carry out a DPIA where Article 35 applies. It also calls for records and logs, and security controls such as encryption, scoped credentials, retention limits and threat testing.

For high-risk AI systems, the EU AI Act requires that the system can be effectively overseen by natural persons while in use. Whether your agent is high-risk depends on its use, so check the classification for each workflow. The application dates for some obligations have been subject to change, so confirm the current timetable on the official EU pages.

UK readers should note that the UK has its own data protection regime, and the EU rules apply when you process the personal data of people in the EU. A short checklist:

Perspective: governance multiplied by throughput

We build AgentWorks on one conviction: an agent is only as valuable as the trust a business can place in it. Throughput without governance simply produces errors faster.

That is why servers, AI models and integrations run exclusively within the EU, and why customer data is never used to train models. For teams handling customer and supplier data, data residency is a design requirement, not a footnote.

It is also why approvals are built in. When an agent sends, books or changes data, a person confirms it. Audit logs record what happened. Sector-ready templates mean a regulated team starts from a sensible structure rather than a blank page.

Our advice is to pick one workflow, configure it tightly, and let evidence from the logs decide how far to extend it.

Erwin

Start with a configured workspace

AgentWorks is an EU-based AI workspace where teams configure agents for recurring tasks, connect Outlook, Shopify, Google Drive and other tools, and keep human approvals and audit logs on by default for actions that change things.

Agent-works

Pricing is per run. The Free plan costs €0 one-off. The Business plan is €29 per month per person, or €290 per year per person. Extra workflow runs are available as one-off top-ups from €5 to €400. See the current plans and run allowances or explore the platform at agent-works.ai.

FAQ

What is the difference between a custom AI agent and a chatbot?

A chatbot answers a message and stops. A custom agent works towards a goal, calls tools such as email or a shop system, reads the results and decides the next step. It is configured with your instructions, knowledge and permissions.

Do I need to code to build a custom AI agent for my business?

No, not for most recurring workflows. You define the job, start from a template, connect your tools and set approval rules in a workspace. Coding becomes relevant when you need bespoke logic or integration with proprietary systems.

What should an AI agent template include?

A good template has a clear role, step-by-step instructions, expected inputs, an output format, the relevant tool connections and approval points. You then replace the generic parts with your own policies, tone and data sources.

How do I keep control when I run several agents?

Give each agent one owner, version its instructions, limit its permissions to its job and review logs in one place. Keep human approval on any action that sends, books or changes data.

Sources

Made with the help of BabyLoveGrowth

About the author

· AI agents for European teams

AgentWorks is the AI workspace for European organisations: chat, agents, workflows and tasks, with every model from OpenAI, Anthropic, Google and Mistral hosted in the EU, approval before an agent acts, and every price in euros.

Read more about AgentWorks