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Glossary

Term Meaning in this book
Agent A system that observes state around a goal, selects and executes actions, updates state based on the results, and decides what to do next
Agentic Workflow A workflow that introduces localized dynamic judgment into deterministic orchestration
Bounded Autonomy Autonomy constrained by candidate actions, permissions, budgets, state machines, and evaluation gates
Context Contract An agreement governing the types, sources, permissions, lifecycles, and trustworthiness of information that enters the model context
Context Engineering The practice of building dynamic systems that provide models and tools with the information, capabilities, and constraints needed to complete a task, in the right format and at the right time
Context Pack The typed input contract actually supplied to a model call, including the goal, state, evidence, tools, budget, omissions, and version information
Evidence Decision evidence bound to its source, version, Locator, time, permissions, and the Claim it supports
Source Manifest A registration contract for a data source's Owner, classification, ACL, refresh policy, valid time, deletion policy, parser, and Schema
RAG Retrieval-Augmented Generation, which retrieves external knowledge at generation time and supplies it as model context
Agentic RAG A pattern in which an Agent decides when and how to retrieve as reasoning progresses, supplementing evidence within a bounded loop
Hybrid Retrieval A pattern that combines FTS, Vector, Graph, SQL, or API retrieval according to the query shape, then merges and reranks candidates from multiple paths
GraphRAG A pattern that uses entities, relationships, paths, communities, or graph algorithms to retrieve and organize evidence; specific product implementations may differ
Knowledge Graph A graph describing business entities, relationships, and rules that answers “what is true and what is connected”
Context Graph A graph describing the causal relationships among Goal, Task, Tool, Evidence, and Claim within a single Agent execution
Handoff The explicit transfer of task control and necessary state from one Agent to another
Supervisor An orchestration role responsible for routing, delegation, aggregation, or control across multiple units of responsibility
Central Supervisor A control-plane role responsible for cross-domain Goal decomposition, Team routing, global dependencies, budgets, and result aggregation
Team Supervisor A role that selects a Worker within a single domain, allocates sub-budgets, validates local results, and returns a Team Result externally
Delegation Contract An agreement governing a subtask's goal, acceptance criteria, scope, tools, budget, deadline, and escalation path
Result Contract An agreement governing an Agent task's status, conclusions, evidence references, missing information, side effects, and recommended next steps
Join Contract An aggregation agreement governing the wait set, completion threshold, timeout, conflicts, and late results for parallel tasks
Late Result A result that arrives after a task has timed out or been canceled, or after the Plan has been updated; it should be recorded but must not be merged into the current state by default
Reconcile When the state of an external side effect is unknown, querying the authoritative system and converging local state rather than retrying blindly
Artifact A referenceable output produced by an Agent or tool; production systems should use immutable versions and content hashes
AgentOps A production operations responsibility framework built around Goal, Plan, Route, Tool, Evidence, Decision, and Control to make systems diagnosable, amenable to intervention, recoverable, and continuously optimizable
Capstone An integrated delivery that uses one complete project to close the loop across the problem, architecture, implementation, security, evaluation, release, operations, and maintenance evidence
Vertical Slice An end-to-end slice that uses a minimal capability to traverse real boundaries such as identity, planning, delegation, tools, state, evidence, evaluation, and observability
Evidence Package An acceptance package bound to a specific Release Candidate that brings together product, architecture, implementation, quality, security, resilience, operations, and traceability evidence
Traceability Matrix A set of bidirectional relationships linking Requirement, ADR, Contract, Implementation, Verification, Runtime Evidence, and Sign-off
Release Candidate A candidate release for which the versions of source code, contracts, Prompt, Model, Tool, Policy, Knowledge, artifacts, and evidence have been fixed
Clean-room Reproduction An acceptance method in which an independent environment that does not rely on the author's local machine state or verbal guidance reproduces the system and its evidence by following public instructions
SBOM Software Bill of Materials, an inventory describing the direct and transitive dependencies, versions, identifiers, and licenses contained in a release artifact
Build Provenance Verifiable source information describing who produced an artifact, through which build process, and from which inputs
Artifact Attestation A verifiable, signed statement about an artifact and its provenance, build, or other properties; it does not mean the artifact is free of vulnerabilities
Release Gate A release gate that issues a Pass, Conditional Pass, or Fail decision for an independent risk involving the problem, design, slice, quality, security, or operations
System Acceptance A formal judgment, based on requirements, evidence, risk, and independent reproduction, about whether a system is ready for delivery
Goal Outcome Event A structured operational event describing the goal outcome, safety path, evidence coverage, latency, cost, versions, and correlation references
Tier 1 Metric A goal-level metric that directly expresses the user commitment and overall system health and can change operational decisions
Tier 2 Metric A diagnostic metric that explains changes in Tier 1 by responsibility layer, such as Planner, Router, Worker, Tool, Model, State, and Security
Incident Bundle A transferable fact package that brings together an incident's impact, versions, evidence, control actions, rollback, and timeline
A2A Agent2Agent Protocol, an interoperability protocol through which independent Agent instances discover capabilities, exchange messages, track tasks, and deliver artifacts
AgentCard The discovery object in A2A that describes an Agent's identity, interfaces, capabilities, skills, and security schemes
Capability Snapshot A snapshot derived from an AgentCard or Registry and supplied to the Planner after filtering by user, tenant, environment, version, and risk
Tool Call A structured action proposal generated by a model; it must be parsed, validated, and authorized before execution
Tool Contract The complete contract for a tool's name, purpose, input Schema, permissions, errors, idempotency, and side effects
State Structured runtime data shared by an Agent across steps, including task, evidence, control, and correlation information
Checkpoint A state snapshot saved at a state-graph step boundary for pausing, resuming, replay, and failure analysis
Idempotency The property that repeated requests for the same business action produce no additional side effects or return the same result
MCP Model Context Protocol, a standard protocol through which an AI Host and external Server discover, read, and invoke capabilities
Golden Dataset A governed, repeatable collection of evaluation case contracts that represents critical risks; it includes inputs, facts, evidence, path invariants, tolerances, and provenance
Golden Entry A single versioned case in a Golden Dataset that describes inputs, expected facts and evidence, allowed and prohibited behaviors, execution policies, and governance metadata
Evaluation Contract An agreement governing quality attributes, affected populations, calculation methods, evaluators, slices, thresholds, gates, and Owner
Evaluator Code, domain rules, an LLM Judge, or a human review mechanism that produces structured measurements or verdicts for one or more Agent runs
LLM-as-a-Judge A measurement method that uses a language model to evaluate open-ended output or perform pairwise comparisons against an explicit Rubric; it requires calibration, versioning, abstention, and human review
Judge Calibration The process of comparing Judge verdicts with independent human labels to assess agreement rate, Precision, Recall, Kappa, order stability, and slice-level error
Evaluation Slice An evaluation subset divided by intent, risk, language, path, model, tool, or another dimension to reveal differences obscured by the overall average
Holdout Set A reserved evaluation set isolated from development tuning and used for release validation or periodic audits
N-run A method that repeats the same case under declared model parameters, Fixture, cache, and state-reset conditions and analyzes the result distribution
pass@k The probability or observed metric that at least one of k attempts succeeds, commonly used in candidate-generation and search scenarios
pass^k The notation used in this book to indicate that all k runs succeed, emphasizing stable execution; it is not a standardized industry term
Paired Evaluation An evaluation design in which the Baseline and Candidate run on the same cases under controlled conditions and their differences are compared case by case
Regression Gate A quality policy that determines whether a change may enter the next release stage based on hard gates, non-regression tolerances, and performance and cost budgets
Quality Drift The phenomenon in which quality attributes such as goal success, faithfulness, safety, decision quality, or experience change over time or across versions
Data Leakage The phenomenon in which evaluation cases or their semantic neighbors enter training, Few-shot examples, RAG, or Memory, inflating regression scores without representing generalization ability
Trace The observable execution trajectory of planning, routing, tools, state, and output within a task
Control Plane The control plane responsible for routing, planning, policy, budgets, approvals, and state transitions
Runtime Control Plane The runtime control plane that converts production observations into audited actions such as circuit breaking, degradation, cancellation, rate limiting, rollback, and recovery
Control Action Contract An agreement governing a control action's target, scope, reason, approval, expected version, duration, rollback, and recovery conditions
Execution Plane The execution plane that actually runs Agent, Tool, Worker, Sandbox, and model-call workloads
Source of Truth The authoritative source with final decision rights when facts conflict
Derived Index A derived structure generated from an authoritative source to improve query or analysis efficiency and designed to be rebuilt for a specified version
Startup Probe A probe that determines whether an application completes initialization within the allowed time; routine liveness and readiness probes should not run before it succeeds
Liveness Probe A probe that determines whether a process is stuck in an internal failure that requires a restart to recover
Readiness Probe A probe that determines whether the current instance can accept new traffic; failure usually removes it from traffic without restarting it
Synthetic Check A proactive check that uses controlled test requests to validate a critical end-to-end business path
OpenTelemetry An open observability framework for generating, propagating, collecting, and exporting telemetry data such as Trace, Metric, and Log
Baggage Controlled key-value context propagated with a request; it may enter downstream network requests and must not carry sensitive data
SLO Service Level Objective, a target for a user-perceived service metric over a specified window
SLI Service Level Indicator, a computational definition of user-perceived service performance that must declare its population, numerator, denominator, window, and exclusions
Error Budget The unreliability allowance represented by 1 - SLO, used to balance the speed of change against investment in reliability
Error Budget Burn Rate The rate at which an error budget is consumed within a given window, used to identify rapid or sustained reliability degradation
RPO Recovery Point Objective, the acceptable span of data loss after a failure
RTO Recovery Time Objective, the maximum allowed time from a failure until the target service is restored
Circuit Breaker A mechanism that fails fast during sustained downstream failures and uses controlled probes to determine whether service has recovered
Bulkhead A mechanism that isolates concurrency and failures by task, tenant, tool, or resource pool
Backpressure A mechanism that suppresses upstream input through rejection, bounded queues, rate limiting, or degradation when the system is overloaded
Retry Amplification The ratio of total physical attempts to unique logical operations, used to identify load and cost amplification caused by retries stacking across layers
Cost per Successful Goal A unit-economics metric that divides total effective cost by the number of successful Goals, linking technical consumption to business outcomes
Wasted Cost Model, tool, and platform costs incurred by work that fails, is discarded, is duplicated, or does not contribute to the final result
Semantic Cache A cache that matches semantically equivalent requests or intermediate results by intent, entity, permissions, version, and valid time; every hit must re-satisfy isolation and evidence constraints
Experience Store A store of reusable operational experience governed for provenance, human review, scope, validity period, privacy, and version compatibility
Prompt Release Manifest A release manifest that records the Prompt version, code commit, variables, compatibility contracts, evaluations, canary rollout, excluded risks, rollback, and Owner
GameDay An exercise that injects failures in a controlled, production-like environment to jointly validate the system, people, processes, alerts, Runbook, and recovery capabilities
ORR Operational Readiness Review, a production-readiness review that uses SLO, quality, security, recovery, operations, cost, and exercise evidence to make a Go, Conditional Go, or No-Go decision
Break-glass A controlled mechanism for temporarily elevating privileges or bypassing normal access procedures in an emergency; it must have an explicit scope, approval, TTL, and audit trail
DLQ Dead Letter Queue, a queue that retains messages that have reached their retry limit or cannot be processed, pending diagnosis and controlled replay
Prompt Injection An attack in which an attacker influences a model's goals, decisions, or output through user input, retrieved content, tool results, or other channels
Indirect Prompt Injection Malicious instructions that do not come directly from the user but are hidden in web pages, emails, documents, OCR, tool results, or Peer Agent content
Least Agency An Agent security principle that grants the minimum functionality, permissions, and autonomy, and only when genuinely necessary
Tool Guard An architectural role between the model's Tool Intent and a privileged executor that enforces identity checks, policy, Schema validation, risk controls, approvals, and result gates
Policy Enforcement Point A deterministic control point that intercepts access or action requests and enforces a Policy Decision
Workload Identity A machine identity representing a service, Agent, Worker, or Tool Runtime, separate from the end user's identity
Effective Authority The effective intersection of permissions from the user, Workload, delegation, task, tool, resource, environment, and approval
Bound Approval An approval authorization bound to a specific action, resource, parameter hash, version, Scope, and validity period
TOCTOU Time of Check to Time of Use, the problem in which a state change between a successful check and execution invalidates the earlier authorization
Confused Deputy A problem in which a low-privilege principal induces a high-privilege service to use its own authority to perform an action that the original principal is not authorized to perform
Token Audience The target resource service for which an Access Token is issued; the recipient must verify that it is the intended audience
DLP Data Loss Prevention, the discovery, classification, transformation, blocking, and exfiltration monitoring of sensitive data
Security Invariant A zero-tolerance security condition that cannot be consumed through a statistical error budget; for example, unauthorized side effects must remain at zero
Attack Success Rate The proportion of attacks that achieve a prohibited objective within a specified attack set, version, and number of repetitions
Red Team An activity that simulates attacks within an explicit scope and safety constraints to validate control, detection, response, and recovery capabilities
Fail Closed Denying a protected action by default when a control or dependency fails, preventing policy bypass when a security component is unavailable
Nonce A random or unique value used only once to detect replay of messages, approvals, or delegations
ADR Architecture Decision Record, which records context, constraints, options, the decision, and the verification method