What AI agents are
How models, tools, memory, and control loops combine into systems that can carry out multi-step work.
An AI agent is not a separate kind of intelligence. It is usually a language model placed inside a software loop that can inspect a situation, choose an action, use a tool, observe the result, and continue until it reaches a stopping condition.
The basic loop
A simple agent repeats four steps:
- Read the goal and current state.
- Decide on the next useful action.
- Call a tool, such as search, code execution, or a business API.
- Inspect the result and update the plan.
The model provides flexible reasoning and language handling. Conventional software provides permissions, tool definitions, timeouts, logs, and other controls that make the loop usable.
Tools turn text into action
Without tools, a model can only produce output. Tools let it retrieve current information, modify files, query a database, or operate another service. Each tool should have a narrow interface and clear validation. Broad, ambiguous tools make mistakes harder to predict and contain.
Permissions matter as much as capability. Reading a calendar is different from cancelling an event; drafting an email is different from sending it. Good agent design keeps those boundaries explicit.
Memory has several meanings
Agent “memory” may refer to the current conversation, saved user preferences, a retrieval index, or a structured task state. These are different systems with different risks. Useful memory is selective: it stores what will matter later and avoids collecting unrelated sensitive information.
Autonomy is a design choice
An agent does not need maximum autonomy to be useful. Many strong workflows mix automation with checkpoints: the system researches and drafts independently, then asks for approval before an irreversible action.
The right level depends on the cost of error. Reversible, observable work can be more autonomous. Payments, publishing, access changes, and destructive actions need tighter confirmation and audit trails.