Glossary
Terms and definitions used throughout this catalog, organized alphabetically.
A
Agent
A system that uses a language model to perceive its environment, make decisions, and take actions toward a goal. Agents typically have access to tools and maintain some form of memory. See Agents.
Agentic System
An AI application exhibiting autonomous behavior — goal-directed actions, tool use, planning, and self-correction with minimal human intervention. Exists on a spectrum from simple tool use to open-ended goal pursuit.
Autonomy
The degree to which an agent operates without human intervention. Ranges from human-approval-at-every-step to fully autonomous execution. Higher autonomy increases throughput but reduces control.
C
Chain of Thought (CoT)
A reasoning technique where the model shows step-by-step logic before reaching a conclusion. Improves accuracy on complex tasks by making intermediate reasoning explicit. See Chain of Thought.
Citation
Linking generated output back to source documents or data. Provides verifiability and reduces hallucination risk. See Citation.
Context Rot
The gradual degradation of model performance as the context window fills with irrelevant or stale information. A key symptom of the Amnesiac Agent anti-pattern.
Context Window
The maximum number of tokens a language model can process in a single request — system prompt, conversation history, tool results, and response combined. Larger windows don't guarantee better attention across all content.
D
Delegation
Passing a subtask from one agent to another. Central to Orchestrator and Hierarchical patterns.
E
Embedding
A numerical vector representation of text that captures semantic meaning. Used for similarity search in Vector Store memory and RAG.
Eval Suite
A collection of test cases, scoring rubrics, and benchmarks used to systematically measure agent output quality. See Eval Suite.
Evaluator-Optimizer
An orchestration pattern where a generator produces output and a critic scores it in a refinement loop. See Evaluator-Optimizer.
F
Fan-Out / Fan-In
Splitting a task into concurrent subtasks (fan-out) and aggregating results (fan-in). The core mechanism of the Parallel pattern.
Few-Shot Prompting
Including examples in the prompt to demonstrate desired behavior. Contrast with zero-shot (no examples) and many-shot (large numbers of examples).
Function Calling
The ability of a language model to output structured requests to execute external functions. The mechanism behind Tool Router and all tool integration patterns.
G
Grounding
Connecting model outputs to external sources of truth — databases, search results, documents — to improve factual accuracy. RAG and Citation are grounding patterns.
Guardrails
Validation layers that check agent output for safety, compliance, factual accuracy, or format correctness before delivery. See Guardrails.
H
Hallucination
When a model generates false or unsupported information with apparent confidence. Mitigated by RAG, Citation, and Guardrails.
Human-in-the-Loop
Inserting human approval or review checkpoints into an agent workflow. Trades throughput for control at high-stakes decision points. See Human-in-the-Loop.
J
JSON Schema
A vocabulary for defining the structure and constraints of JSON data. Used by Structured Output to enforce typed responses from language models.
K
Knowledge Graph
A graph-structured representation of entities and their relationships. Used as a memory pattern for complex, interconnected information. See Knowledge Graph.
L
LLM (Large Language Model)
A neural network trained on large text corpora that can generate, analyze, and transform text. The reasoning engine at the core of agentic systems.
LLM-as-Judge
Using a language model to evaluate and score the output of another model or agent. See LLM-as-Judge.
M
MCP (Model Context Protocol)
A standardized protocol for dynamic tool discovery and invocation. Allows agents to find and use tools at runtime without hardcoded integrations. See MCP.
Memory
State that persists across agent interactions. Categories include conversation buffers, summaries, vector stores, extracted facts, file-based persistence, knowledge graphs, and shared memory. See Memory patterns.
Multi-Agent System
An architecture using multiple specialized agents that coordinate to accomplish tasks beyond any single agent's capability. Includes Role-Based, Hierarchical, and Swarm structures.
O
Observation
In the ReAct loop, the result returned by a tool after an action is executed. Feeds back into the agent's next reasoning step.
Orchestration
The coordination of multiple agents or processing steps — routing requests, managing workflows, aggregating results, and handling failures. See Orchestration patterns.
P
Pipeline
A fixed sequence of processing steps where each step's output feeds the next, with optional validation gates between stages. See Pipeline.
Plan-and-Execute
A reasoning pattern where the agent creates an explicit plan before taking action, then executes steps sequentially with optional replanning. See Plan-and-Execute.
Prompt
Instructions given to a language model. Includes system prompts (persistent instructions), user prompts (requests), and assistant messages (model outputs).
Prompt Injection
An attack where untrusted input manipulates agent behavior by embedding instructions that override the system prompt. A key concern in the Happy Path Mirage anti-pattern.
R
RAG (Retrieval-Augmented Generation)
A pattern that retrieves relevant documents or data before generation, providing context the model can reference. Reduces hallucination and enables access to current or private information. See RAG.
ReAct
A reasoning pattern that interleaves Thought, Action, and Observation steps in a loop. The agent reasons about what to do, executes a tool, observes the result, and repeats. See ReAct.
Reflection
A reasoning pattern where the agent critiques its own output and revises it. Can be self-reflection (same model) or cross-reflection (separate critic). See Reflection.
Router
An orchestration pattern that classifies incoming requests and dispatches them to specialized handlers. Single-pass decision with no iteration. See Router.
S
Sandbox
An isolated execution environment for running agent-generated code safely. Prevents file system access, network calls, or other side effects. Central to Code Execution.
Scoring Rubric
A structured set of criteria used to evaluate agent output. Defines what "good" looks like across dimensions like accuracy, completeness, and safety. Used in LLM-as-Judge and Eval Suite.
Streaming
Delivering agent output progressively as tokens are generated rather than waiting for the complete response. See Streaming.
Structured Output
Constraining model output to conform to a predefined schema — JSON, XML, or typed objects. See Structured Output.
Summarization
Compressing conversation history or documents into shorter representations that preserve key information. See Conversation Summarization.
Swarm
A multi-agent architecture where peers self-organize without a central controller. Agents communicate through shared state and handoff protocols. See Swarm.
System Prompt
Persistent instructions that define an agent's role, constraints, and behavior. Remains constant across user interactions within a session.
T
Temperature
A parameter controlling randomness in model output. Lower values (0.0–0.3) produce deterministic, focused responses. Higher values (0.7–1.0) increase creativity and variation.
Token
The basic unit of text processing for LLMs. Roughly 3–4 characters in English. Pricing, rate limits, and context windows are all measured in tokens.
Tool
An external capability an agent can invoke — APIs, databases, code execution, file systems, or other agents. Tools extend what agents can accomplish beyond text generation.
Tracing
Recording the full sequence of an agent's reasoning steps, tool calls, and decisions. Essential for debugging, evaluation, and observability in production systems.
V
Validation Gate
A checkpoint in a Pipeline that verifies output quality, format, or safety before passing data to the next stage. Fails fast on bad input.
Vector Database
A database optimized for storing and querying embeddings by similarity. Powers semantic search in RAG and Vector Store memory.
W
Worker
A specialized agent that handles a specific subtask assigned by an Orchestrator. Workers are typically narrow in scope and stateless.
Workflow
A defined sequence of steps or agent interactions to accomplish a task. Can be fixed (pipeline) or dynamic (orchestrator-driven).
Z
Zero-Shot
Prompting a model to perform a task without providing examples. Relies entirely on the model's pre-trained knowledge and instruction-following ability.