5.5 Section 5 Master Takeaway (Rapid Exam Cram)
1. The 4 Checkpoints at a Glance
Section titled “1. The 4 Checkpoints at a Glance”5.1 The Perimeter
Agent Gateway + Model Armor
Screens prompts and responses. Single SDP match = Redact & continue. Multi-detector violation = Hard BLOCK.
5.2 Identity & Access
Agent Identity, PAB & OAuth
Unique managed Agent Identity (never shared service accounts!), PAB for resource eligibility, and OAuth 2.0 Auth Manager for user delegation.
5.3 Runtime Guardrails
ADK Callbacks & HITL
Inspect live parameters deterministically in code. Pause high-risk tool executions for Tool-Level HITL, or escalate chats via CES.
5.4 Fleet Governance
ADC, App Hub & Registry
Standardize templates in Application Design Center, track ownership in App Hub, and catalog agents + MCP tools in Agent Registry.
2. Master “If You See X, Pick Y” Decision Matrix
Section titled “2. Master “If You See X, Pick Y” Decision Matrix”| If the Exam Scenario Asks You To… | Always Pick This Solution | Never Pick This Trap! |
|---|---|---|
| Screen prompts/responses for jailbreaks, toxic content, or PII | Agent Gateway + Model Armor (with roles/modelarmor.calloutUser & roles/modelarmor.user) |
Custom regex scripts or relying on “polite system prompts” |
| Stop a “Confused Deputy” attack when an agent calls user-specific tools | OAuth 2.0 User Delegation via Agent Identity Auth Manager | A single shared GCP Service Account with broad permissions |
| Prevent an agent identity from ever accessing resources outside its folder | Principal Access Boundary (PAB) (strips resource eligibility) | Standard IAM Allow roles (which grant access rather than bounding eligibility) |
Block or require human approval when a tool parameter exceeds a limit (e.g., $50,000) |
Deterministic Runtime Guardrail / ADK Before-Tool Callback + Tool-Level HITL | IAM policies or PAB (cloud IAM cannot inspect tool arguments!) |
| Transfer a frustrated customer to a live contact-center representative | Customer Engagement Suite (CES) / CX Agent Studio Conversation Handoff | Pausing a single backend API call without transferring the chat transcript |
| Eliminate “Shadow AI” and discover approved enterprise A2A agents & MCP tools | Agent Registry (linked to App Hub for application topology) | Storing tool URLs in unmanaged spreadsheets or code comments |