Hierarchical Agent Safety Architecture

Hierarchical agent architectures organize agents into layers where each layer has different trust levels, capabilities, and oversight responsibilities. Higher layers constrain lower layers. This structure mirrors established patterns in operating system security and organizational management, adapted for AI agent systems.

Layer Structure

A typical hierarchy has three layers:

Orchestration layer: Top-level agents that decompose tasks, assign work, and aggregate results. These agents have broad visibility but limited direct tool access. They enforce high-level policies and route work to appropriate subordinates.

Execution layer: Mid-level agents that perform specific tasks like research, writing, or data processing. They have tool access scoped to their function. They report results upward and receive instructions only from the orchestration layer.

Tool layer: The lowest level, consisting of direct tool interfaces with strict input validation and output filtering. These are not full agents but constrained functions that execute single operations.

Safety Properties

This hierarchy provides several safety properties by construction. The execution layer cannot bypass the orchestration layer to communicate directly with other execution agents. The tool layer cannot initiate actions without a request from the execution layer. Each layer validates inputs from the layer below and outputs to the layer above.

Policy Enforcement by Layer

Authensor policies can encode layer-specific rules:

rules:
  - principal_layer: "execution"
    action: "tool.*"
    effect: "allow"
  - principal_layer: "execution"
    action: "agent.instruct"
    effect: "deny"

This prevents execution-layer agents from instructing other agents while allowing them to use tools.

Failure Containment

When an execution-layer agent fails, the orchestration layer detects the failure and can reassign the task, terminate the agent, or escalate to a human operator. The failure does not propagate laterally because execution agents cannot communicate with each other directly.

Hierarchical architecture does not eliminate risk. It structures risk into manageable, auditable compartments where each layer's failure modes are well understood and contained.