Chapter 7: Agentic Design Patterns

Behavioral Patterns for Production Agent Systems

Overview

Production agent systems fail far less often because of model limitations than because of behavioral instability. Agents act prematurely, over-plan trivial workflows, retry failing tools without classification, accumulate ungoverned memory, or diverge from user intent as tasks grow in complexity.

Key Insight

Agent reliability is primarily governed by architectural behavior patterns rather than individual model capability. Agentic design patterns serve as architectural control surfaces that provide stable reasoning, execution, and governance structures.

🧠 Cognitive Reasoning

How agents decide: reactive, deliberative, goal-seeking, self-reflective, RwO

⚡ ARC+ Execution

How agents act and recover: ReAct, reflect-replan-retry, feedback recovery

🔍 Advanced Search

How agents explore: tree-of-thought, graph-of-thought, Monte Carlo, consensus

🤝 Multi-Agent Coordination

How agents collaborate: manager-worker, debate-arbitration, ensembles

💾 Memory Governance

How agents learn: episodic retention, semantic updates, procedural evolution

🛡️ Safety & Skills

How agents are deployed: packaged skills, policy enforcement, audit trails

Cognitive Reasoning Patterns

Cognitive reasoning patterns define how an agent determines its next action. Production systems dynamically select reasoning modes based on uncertainty, task risk, latency requirements, and available verification mechanisms.

1. Reactive Pattern

Prioritizes latency, determinism, and throughput with minimal planning.

pattern: reactive
routing:
  - match: "reset password"
    tool: identity.reset_password
    requires_confirmation: true
  - match: "invoice status"
    tool: billing.lookup_invoice
  - match: "shipping"
    tool: logistics.track_package
fallback:
  mode: deliberative
telemetry:
  log:
    - route
    - tool_name
    - tool_status
    - latency_ms

Best For: High-volume transactional workflows (status lookup, credential reset, invoice retrieval)

Failure Modes: Silent tool misuse, overconfident actions under ambiguity

2. Deliberative Pattern

Constructs explicit execution plans prior to tool invocation with structured validation.

pattern: deliberative
plan_schema:
  steps:
    - id: string
      intent: string
      tool: string
      success_criteria: string
      rollback: string
constraints:
  max_steps: 10
  cost_budget_usd: 0.75
execution:
  step_mode: sequential
  replan_on:
    - tool_error
    - contradiction
    - low_confidence

Best For: Multi-step workflows with dependencies, cost management, risk control

3. Goal-Seeking Pattern

Maintains target system state and iteratively minimizes divergence.

pattern: goal_seeking
goal_state:
  definition: "Complete onboarding packet"
progress_signals:
  - checklist_items_completed
  - missing_artifacts_count
stop_conditions:
  - checklist_items_completed == 1.0
  - attempts >= 3 -> escalate_to_human

Best For: State convergence tasks with measurable progress signals

4. Self-Reflective Pattern

Evaluates own outputs through structured critique loops before final response.

pattern: self_reflective
max_reflection_rounds: 2
rubric:
  axes:
    - factuality
    - completeness
    - policy
    - style
stop_if:
  - score >= 0.92
  - delta_improvement < 0.02

Best For: High-quality content generation requiring refinement

5. Reasoning Without Observation (RwO)

Internal planning and hypothesis generation followed by external verification.

pattern: rwo_then_verify
phase_1:
  mode: reasoning_without_observation
  output: candidate_plan
phase_2:
  mode: verify_with_tools
  checks:
    - retrieve_policy_docs
    - validate_tool_permissions
    - confirm_user_intent
phase_3:
  mode: execute_deliberatively

Best For: Complex planning requiring validation before execution

ARC+ Execution Patterns

ARC+ extends classical Action-Reasoning Coupling loops by introducing explicit execution state management, failure classification, recovery ladders, and observability instrumentation.

1. ReAct Execution Loop

Interleaves reasoning, tool invocation, and observation in iterative control loop.

pattern: react
loop:
  while task_not_complete:
    step_1: reason
    step_2: call_tool
    step_3: observe_output
    step_4: update_state
termination:
  - goal_state_reached
  - budget_exhausted
  - escalation_triggered

Benefits: Grounds reasoning through real-world feedback, reduces hallucination

Risks: Unbounded loops without governance, oscillating reasoning branches

2. Reflect-Replan-Retry Pattern

Structured recovery when execution failures occur with failure classification.

pattern: reflect_replan_retry
on_tool_failure:
  classify_failure:
    - transient
    - deterministic
    - policy_violation
  reflect:
    analyze_failure_context
  replan:
    modify_tool_parameters
    OR
    select_alternative_tool
  retry:
    bounded_attempts: 2
  escalate:
    if failure_persists

Benefits: Differentiates transient vs deterministic failures, reduces cascading errors

3. Tool Feedback Recovery Pattern

Cross-validates results across redundant or complementary tool sources.

pattern: tool_feedback_recovery
primary_tool_call:
  result_A
secondary_validation:
  result_B
consistency_check:
  if mismatch:
    invoke_third_source
resolution_strategy:
  majority_vote
  OR
  weighted_confidence

Best For: High-stakes workflows (compliance auditing, financial reconciliation)

4. Execution Budget Governance

Enforces cost, latency, and safety boundaries across ARC+ loops.

budget_control:
  max_tool_calls: 15
  max_execution_time_sec: 60
  max_token_budget: 15000
on_budget_violation:
  trigger_escalation
  OR
  degrade_response_mode

Benefits: Prevents pathological execution cycles, controls costs

Multi-Agent Coordination Patterns

These patterns distribute cognition, execution, and evaluation across specialized agents through structured interaction protocols.

1. Manager-Worker Pattern

Hierarchical decomposition with central coordination and specialized workers.

  • Manager assigns tasks based on worker capabilities
  • Workers execute independently with scoped tools
  • Results aggregated by manager

2. Debate-Arbitration Pattern

Multiple agents propose competing solutions, arbiter selects best.

  • Improves decision quality under uncertainty
  • Reduces single-agent bias
  • Requires explicit scoring criteria

3. Ensemble Integration Pattern

Combines specialist outputs through consensus or weighted voting.

  • Domain specialists contribute independently
  • Outputs integrated via majority vote or confidence weighting
  • Improves robustness and coverage

Why Design Patterns Matter

Agentic design patterns transform agents from unpredictable black boxes into governable, observable, and resilient production systems with architectural control surfaces.