How AI agents actually work.
The infographic gets the central idea right: agents combine models with tools and iterative control. But it compresses important distinctions—and its guardrail model is too thin for production systems. This page rebuilds the concept around current engineering guidance.
What needs correcting?
- Workflow → agent is not a maturity ladder. They are different orchestration patterns; a workflow can be the better design.
- The “agent decides” statement needs boundaries. The model chooses within permissions, code, policies, budgets and stop conditions.
- The loop is a useful abstraction, not a universal protocol. Many runtimes reduce it to repeated model calls + tool execution.
- Guardrails are more than input/output filters. Authorization, sandboxing, approvals, least privilege, tracing and rollback matter.
Replace the ladder with a decision model.
Anthropic explicitly distinguishes workflows—where LLMs and tools are orchestrated through predefined code paths—from agents, where an LLM dynamically directs its own process and tool use. One is not automatically “more advanced” or better.
Model
Generates, classifies or reasons from supplied context. No external action unless the application gives it tools.
LLM / multimodal modelAugmentation
Add retrieval, memory/state, tools, structured outputs, policies and context management.
capabilities + contextOrchestration choice
Use deterministic workflows when the path is known; agentic control when the next step must be chosen at runtime.
workflow ⇄ agentRuntime + controls
Execute tools, observe results, enforce permissions, approvals, budgets, stop conditions and tracing.
production systemFact-check, line by line.
Useful progression, wrong implication.
Models can be augmented with tools and retrieval, but workflow and agent are better treated as alternative orchestration patterns than sequential maturity levels.
Broadly accurate.
Predefined orchestration is the defining distinction in Anthropic’s workflow framing. Workflows can still contain branches, routers, evaluators and LLM calls.
Correct only inside a bounded runtime.
The model can select next actions dynamically, but developers still define available tools, permissions, instructions, maximum turns, budgets, approval gates and termination rules.
A sound mental model, not a standard.
ReAct-style loops are widely used conceptually. Production frameworks may implement the loop more simply as repeated model calls and tool execution until a stop condition.
Representative action set.
OpenAI’s agent guidance explicitly includes tool calls and handoffs; final output is also a standard termination path.
True—with hard limits recommended.
Agent loops can run for variable numbers of steps, but production systems should enforce maximum turns, timeouts, cost budgets and failure thresholds to prevent runaway execution.
Good start, insufficient security model.
Stage-level validation is useful, but tools that affect the outside world require authentication, authorization, least privilege, human approval for high-risk actions, sandboxing where appropriate, and auditability.
Tool results can be adversarial.
Retrieved pages, files, emails and external tool outputs may contain prompt injection or poisoned instructions. They should be treated as untrusted data, not automatically as higher-priority instructions.
Strongly supported.
NIST describes the leading agent paradigm as general-purpose AI models embedded in software scaffolding that enables tool manipulation and actions beyond simple text generation.
Watch a bounded agent loop.
This simulation deliberately makes the hidden production controls visible. The model proposes actions; the runtime checks policy and executes only permitted actions.
Agent loop simulator
Task: “Find the latest invoice and prepare a refund draft.”
Production agent control plane
The infographic becomes substantially safer once these layers are explicit.
When should you use an agent?
OpenAI’s guidance is pragmatic: use agents where decision-making is complex, rule systems are brittle, or unstructured data dominates. If a deterministic solution works reliably, it can be the better engineering choice.
| Situation | Workflow | Agent | Why |
|---|---|---|---|
| Known sequence, stable rules | Excellent | Usually unnecessary | Lower variance, easier testing and lower cost. |
| Dynamic research across sources | Possible | Strong fit | Next steps depend on evidence discovered at runtime. |
| High-stakes financial action | Preferred execution path | Useful for analysis only | Keep irreversible actions behind deterministic checks and human approval. |
| Customer service triage | Strong baseline | Strong with escalation | Agent can interpret messy requests and choose tools, while policy gates constrain outcomes. |
| Simple data transformation | Excellent | Poor fit | No benefit from extra autonomy or iterative reasoning. |
Primary sources used.
The fact-check prioritizes first-party engineering guidance and standards bodies rather than secondary explainers.