Technical Guide
Agent-to-Agent Delegation Security: Risks and Controls
Agent-to-agent delegation security requires scoping identity and permissions per delegation hop, enforcing policy at each tool-call boundary, and logging the full delegation chain, rather than relying on the broad, shared credentials common in current multi-agent architectures.
Where Delegation Introduces Risk
When one agent hands off a task or tool access to another agent, four areas of risk consistently appear across multi-agent architectures.
Identity Propagation
Requester context can be lost as tasks pass across multiple agent hops.
Permission Scoping
Shared, broad-permission credentials let delegated agents exceed intended authority.
Tool-Call Governance
Authorization decisions must occur at each invocation, not just at system entry.
Auditability
Multi-hop, asynchronous execution complicates reconstruction of action chains.
Architectural Principle
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Design Runtime Controls Into the Architecture
Runtime controls for agent-to-agent delegation should be designed into the architecture rather than layered on afterward.
The Full Guide
What Agent-to-Agent Delegation Is
Agent-to-agent delegation occurs when one AI agent passes a task, along with some degree of tool access or authority, to another agent in order to complete a larger workflow. This pattern is increasingly common in enterprise deployments where a coordinating agent breaks a request into subtasks and routes each one to a specialized agent.
Why This Is a Distinct Threat Model
Delegation between agents does not behave like a single agent calling a single tool. Each hop introduces its own opportunity for identity to be dropped, permissions to be broadened rather than narrowed, and authorization checks to be skipped on the assumption that an earlier step already verified them. Because of this, delegation security cannot be treated as an extension of standard tool-call security; it requires its own controls at each boundary in the chain.
Specific Failure Modes
- Requester identity and context are lost or diluted as a task passes across multiple agents.
- Shared, broad-permission credentials allow a delegated agent to take actions beyond what the original task required.
- Downstream agents invoke tools without a fresh authorization check, trusting that upstream authentication was sufficient.
- Asynchronous or branching execution makes it difficult to reconstruct which agent took which action on behalf of which requester.
Governance Considerations
Addressing these failure modes requires treating each delegation hop as its own security boundary. That means scoping credentials per task rather than per workflow, checking policy at the point of tool invocation rather than only at system entry, and maintaining logs that are structured enough to trace a single action back through every agent that touched it.
Evaluation Questions for Governance Leaders
Teams assessing a multi-agent deployment should be able to answer: which agent originated a given action, what permissions it held at the time, whether that scope was verified at each hop, and whether the full chain can be reconstructed after the fact.
Implementation Checklist for Delegation Security
- Confirm the agent framework and any protocol in use (such as MCP) supports explicit authorization hooks rather than assuming built-in delegation security.
- Replace shared, broad-permission API keys or service identities with short-lived, task-scoped credentials per delegation.
- Apply least-privilege IAM or service-account scoping to each agent role individually, not to the workflow as a whole.
- Insert policy enforcement checks at every tool-call boundary, including intermediate agent-to-agent hops.
- Generate centralized logs that capture the delegating agent, receiving agent, invoked tool, and originating requester for every action.
- Test explicitly for privilege escalation paths where a lower-privileged agent can gain higher-privileged tool access through delegation.
Runtime Controls Mapped to Risk
Each delegation risk has a corresponding control, drawn from established guidance rather than novel practice.
| Risk | Corresponding Control |
|---|---|
| Privilege escalation | Least-privilege scoping applied per agent role, consistent with cloud-provider guidance from AWS, Google Cloud, and Microsoft, which recommend narrow IAM or service-account permissions for each automated workload rather than broad, reusable grants. |
| Loss of accountability | Centralized, structured logging that captures the delegating agent, the receiving agent, the tool invoked, and the outcome, similar to the CloudTrail-style logging recommended for generative AI workloads. |
| Unauthorized tool invocation | Tool-call governance: policy checks at the point of invocation that verify the calling agent's scope matches the requested action, rather than trusting that upstream authentication was sufficient. |
| Untraceable action chains | A verifiable identity chain and correlation IDs maintained across the full delegation path, including asynchronous branches. |
Bring Runtime Governance to Multi-Agent Delegation
Trussed AI provides runtime governance and security for enterprise AI agents, including identity, permissions, tool-call policy enforcement, and audit logging for agent-to-agent workflows.
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