Agent Training Data: A Guide to LLM-Based Agent Training

Agents based on Big Language Models (LLMs) are now changing the way businesses, researchers, and developers interact with data and make decisions. The success of these agents depends on the model architecture, quality, diversity, and management of the training data.

This guide provides an overview of the sources, generation methods, curation strategies, and practices for data preparation. This allows LLM-based agents to operate safely and effectively in real-world environments.

Quick Take

  • Quality input data ensures reliable results.
  • To connect datasets to measurable tasks, operational roles need to be defined.
  • Blended strategies help strike a balance between speed, security, and scale.
  • Methods improve efficiency, reduce evaluation time, and control costs.
  • Human feedback and explanatory information minimize production risk.

Agent training data

Training LLM agents depends on the quality and provenance of the training data for agents. Agents learn to perceive context, plan actions, interact with the environment, and make decisions. Therefore, the data for them must cover real-world scenarios, synthetic interactions, and be carefully curated.

Category

Subtype

Short Description

Why It Matters for Agents

Data Sources

Real data

User logs, business documents, system telemetry

Shapes realistic behavior in live environments


Public datasets

Open text, code, and RL datasets

Provide general knowledge and reasoning patterns


Expert-generated data

Scenarios and decisions from domain experts

Ensures correct logic and reduces errors

Data Generation

Synthetic data

Data generated by LLMs or simulators

Scales training and covers edge cases


Self-play/Multi-agent

Agents interact and learn from each other

Teaches strategies rather than fixed responses


Reinforcement learning data

Environment interaction via reward signals

Optimizes decision-making and action sequences

Data Curation

Cleaning and filtering

Removing noise, duplicates, unsafe content

Improves reliability and safety


Annotation

Labeling goals, actions, and outcomes

Enables causal and structured reasoning


Debiasing

Detecting and mitigating data biases

Produces fair and stable agent behavior


Versioning and lineage

Tracking data origin and changes

Ensures reproducibility and enterprise control

Data quality and representativeness

For LLM agents, quality data is data that has logic and thought patterns that they internalize.

Quality measurements:

  • Accuracy. The data reflects real facts, events, or correct decisions.
  • Completeness. There are no gaps in scenarios, roles, or contexts.
  • Timeliness. The data is relevant to current conditions, rules, and policies.
  • Consistency. There are no logical contradictions between sources.
  • Noise vs. Signal. Useful information dominates over random or irrelevant samples.

Data representativeness

Representativeness means that the data accurately reflect the real distribution of the environment in which the agent operates. Let's consider the main aspects of representativeness:

  • Scenario coverage. There are typical and rare cases in the data.
  • Balance of roles and contexts. Different types of users, languages, and interaction styles.
  • Distribution of actions and decisions. Not only "successful" or "ideal" cases.
  • Correspondence to the environment. The data corresponds to the real conditions of use.

So, quality determines how correctly the agent thinks, representative of how widely it is ready to act.

LLM annotation | Keymakr

Labeling and feedback

Labeling is the process of assigning a structured meaning to data that an agent can use to learn not only responses, but also behaviors and decisions. Unlike classical models, agents need multi-level annotations:

  • Goal — what the agent needs to achieve
  • State — the context in which the decision is made
  • Action — a specific step or tool call
  • Outcome — the consequence of the action
  • Quality of the decision — correct/acceptable/incorrect
  • Rationale — why this decision is correct or not

Labeling is performed by domain experts from various fields, trained annotators, or other models (such as auto-labeling with verification).

Feedback

Feedback is a signal that the agent receives after an action and uses it to correct its behavior. By collecting preference data from human evaluators, such as ranking outputs or providing feedback. Agents can learn which actions or responses are preferred, further improving performance and alignment.

Types of feedback:

Type

Description

Use / Pros / Cons

Human Feedback

Response rating, ranking multiple options, comments with explanations

Used in reinforcement learning from human feedback (RLHF) and critical agent training; highly contextual, captures intent

Automatic Feedback

Metrics, rule checks, simulation results

Scalable; drawback: may miss intent or nuanced errors

Hybrid Feedback

Combination of automatic evaluation and selective human review

Most common in enterprise systems; balances scalability and accuracy

Choosing a training approach

There are different approaches to training agents and LLMs that define how the model acquires knowledge and forms behavior. Each method has its own advantages, limitations, and optimal application scenarios. The choice of approach depends on data availability, task complexity, and the requirements for security and accuracy.

Learning Approach

What It Is

Advantages

Disadvantages

Supervised Learning

Model learns from labeled data 

Fast training, high accuracy on known data

Requires many high-quality labels; does not teach strategies

Self-Supervised Learning

Model generates signals from the data itself without external labels

Can leverage large datasets; learns general patterns

Slow to train; may learn noise or undesired patterns

Imitation Learning

Agents learn by observing agent demonstrations or expert behavior

Learns complex action sequences; quickly approximates expert level

Limited to available examples; may not learn optimal strategies

Reinforcement Learning (RL)

Agent learns through rewards and penalties by interacting with the environment

Teaches optimal policies; adaptable to new situations

Slow training; requires careful reward design; risk of undesired behavior

Platforms and tools for training agents

Agent platforms can be categorized based on functionality and intended use:

Type of Platform 

What It Does

Why It’s Needed

Data Management Platforms

Store, version, and curate large datasets

Ensure data quality, representativeness, and reproducibility of training

Annotation/Labeling Tools

Allow experts or annotators to create structured labels for data

Provide clear signals for agent learning and support causal reasoning

Model Training Systems

Enable distributed training, model optimization, and experiment management

Allow efficient training of large models and agents on diverse data types

Simulators/RL Environments

Create controlled environments for agent interaction

Used for reward-based learning and strategy testing

Monitoring & Evaluation Tools

Measure agent performance, track errors, hallucinations, and biases

Ensure safe and stable deployment of agents

Integration & API Services

Allow agents to interact with real-world systems and tools

Enable practical deployment of agents in business workflows

Keymakr specializes in creating high-quality training data for artificial intelligence models, including computer vision and other machine learning applications. The company collects, annotates, verifies, and classifies data, combining human experience with automated validation. This approach ensures high-quality data. Its proprietary

Keylabs data annotation and management platform provides tools for machine labeling, project workflow management, team collaboration, and support for multiple data formats. These tools help organizations prepare consistent and scalable datasets needed to train LLMs and intelligent agents.

Testing and validation

Testing and validation are important stages in the LLM agent lifecycle. The primary goal of these processes is to verify that the agent performs its functions correctly and safely before deploying it for interaction with real users.

The first stage of testing takes place in a sandbox environment. This is a controlled environment that simulates real conditions, but without risk to users. In the sandbox, the agent interacts with synthetic data, simulators or pre-created scenarios. This allows you to evaluate its behavior, reaction to edge-case situations, the correctness of its decisions, and compliance with established rules.

Such testing allows you to detect errors, hallucinations, biases, or unwanted behavior patterns at an early stage.

In the second stage, the agent interacts with real users, a process known as phased rollout or pilot testing. They start with a limited group or test scenarios. It enables you to evaluate the agent in real-world conditions, considering a range of requests, user patterns, and unpredictable contexts.

It is essential to collect user feedback, success metrics, and behavioral data to refine the agent and optimize its actions before a large-scale launch.

The combination of sandboxing and limited user testing allows you to achieve a balance between security and reliability. Without this approach, the agent may exhibit unwanted behavior in critical situations or provide incorrect answers, resulting in a loss of user trust and damage to the business's reputation.

Problems and practical solutions

When training and implementing LLM agents, recurring problems arise that can compromise the system's security for users. It is essential not only to identify these problems but also to develop practical solutions to address them.

Problem

Description

Practical Solution

Low-quality data

Data contains errors, noise, or incorrect examples

Use filtering, expert annotation, and human-in-the-loop verification

Data bias

Incorrect or biased representation of groups, scenarios, or roles

Apply debiasing, dataset balancing, and representativeness checks

Model hallucinations

Agent generates false information or inaccurate answers

Use RLHF, additional verification sources, and confidence-based response limits

Poor reward design

Incorrect reward signals lead to undesired behavior

Design clear reward functions, apply penalties for errors, decompose goals into sub-tasks

Limited generalization

Agent fails to adapt to new scenarios

Train on diverse datasets, use self-play, and synthetic data augmentation

Deployment risks

Agents may make mistakes in real-world environments

Use gradual rollout, sandbox testing, and collect user feedback

FAQ

What sources of supervised and synthetic input data should be used?

Should real, labeled data and synthetically generated scenarios or simulations be used?

How to ensure the quality and representativeness of collections?

Quality and representativeness are ensured by carefully annotating, cleaning data, balancing scenarios, and verifying coverage of all relevant cases.

When is simulation learning better than reinforcement learning approaches?

Simulation learning is better when high-quality demonstrations of expert behavior are available, and strategies need to be quickly reproduced without lengthy trial-and-error.

What are the best practices for annotation and human-in-the-loop feedback?

It is best practice to combine expert labeling with automated validation, regularly assess quality, and provide structured feedback.

What testing and validation regime should precede deployment?

Before deployment, the agent should be sandbox-tested and then validated with a limited group of real users.

What are the common problems and pragmatic strategies to mitigate them?

Common problems include low-quality data, bias, model hallucinations, weak generalization, and deployment risks. Pragmatic strategies include data filtering and annotation, debiasing, RLHF, diverse training sets, sandbox testing, and gradual rollout.