# Agent (Agentic AI)

Source: https://customlabs.io/glossary/agent/
Updated: 2026-09-13

Agents

# Agent (Agentic AI)

An agent is an LLM given a loop, memory, and tools it can call.

It plans multi-step work and takes actions, rather than returning a single answer.

"Agentic" describes a spectrum, from one tool call to a fully autonomous loop, not an on/off feature.

The engineering that matters most is the guardrails, observability, and evals around the loop.

An agent that can act is also an agent that can act wrongly.

[Capabilities](https://customlabs.io/capabilities/)[AI Integrations](https://customlabs.io/services/ai-integrations/)[Field guide: Failure modes](https://customlabs.io/failure-modes/)

[← Back to the full glossary](https://customlabs.io/glossary/)

## Related terms

[Tool Calling Tool calling lets a model request a structured action instead of only generating text.](https://customlabs.io/glossary/tool-calling/)[Guardrails Guardrails are the checks that keep an LLM or agent inside acceptable bounds in production.](https://customlabs.io/glossary/guardrails/)[Observability Observability captures traces of every prompt, retrieval, tool call, and response for debugging.](https://customlabs.io/glossary/observability/)[Eval Suite (Evals) An eval suite is a versioned set of test cases that measures whether outputs are good.](https://customlabs.io/glossary/eval-suite/)

## More in Agents

[Model Context Protocol (MCP) MCP is an open standard for connecting LLM applications to tools and data sources.](https://customlabs.io/glossary/model-context-protocol/)[Context Engineering Context engineering decides what occupies a model's context window at every step, and in what order.](https://customlabs.io/glossary/context-engineering/)[Tool Contract A tool contract is the schema a tool exposes to a model.](https://customlabs.io/glossary/tool-contract/)[Idempotency An idempotent operation produces the same result no matter how many times it runs.](https://customlabs.io/glossary/idempotency/)