Enforce least privilege for retrieval and tool access using role-based and attribute-based rules. The key principle is that retrieval is an access path and must be secured like an API.
Key Takeaways
- • Policy must apply before retrieval, not after generation.
- • Structured data requires row and column controls.
- • Tool access must be explicit, scoped, and audited.
Policy enforcement points
Layered enforcement for both context retrieval and tool execution.
Context access model (RBAC and ABAC)
Use a layered model where RBAC identifies the user and ABAC determines what they are permitted to see in a specific context.
User Attributes
roledepartmentregion
Data Attributes
classificationdomainowner_team
Row and column-level controls
For structured sources, tagging is not enough. If a user is not allowed to query the underlying data directly, the AI system must not retrieve it either.
- • Column masking for sensitive fields
- • Row filtering by region, tenant, or business unit
- • Aggregation-only access where raw records are restricted
- • Strict separation between “metrics” and “raw data”
Tool registry and permissions
Treat tools like APIs. Tool permissions should be explicit per role and scoped for least privilege.
| Requirement | Details |
|---|---|
| Tool Metadata | name, owner, purpose, schema |
| Data Auth | classification of returned data |
| Operational | rate limits, budgets, logging reqs |
Secrets and credential scoping
- • Use short-lived tokens
- • Scope tokens to the minimum dataset or API
- • Never put credentials in prompts
- • Separate execution identity from user identity
GCP mapping
Illustrative. Each layer maps to equivalent services on AWS, Azure, or any cloud.
Policy Engine
IAM + VPC Service Controls
ABAC / Fine-grained
BigQuery row/column security
Tool Gate
Cloud Run + IAM invoker roles
Audit Log
Cloud Audit Logs → BigQuery
Failure modes
- ! “Superuser retriever” bypasses policy and leaks data.
- ! Tool outputs are not validated and return sensitive data.
- ! Policies exist on paper but are not enforced in retrieval.
- ! Too much reliance on prompt instructions vs access control.
Checklist
- □ Policy engine exists and is called before retrieval.
- □ Structured data access respects row and column rules.
- □ Tool registry exists with explicit per-role permissions.
- □ Credentials are short-lived and scoped.
- □ Denied requests are safe and explainable.