Google Genkit tool-calling boundary

Evidence-backed facts

1. Genkit defines typed tools that models can request from flows and agent-style application logic. informative
2. The Genkit runtime executes the registered tool implementation and feeds its output back into generation; the model only proposes the call. informative
3. Model configuration, deployment identity, tool secrets, data access, validation, and approval for external effects remain explicit boundaries. informative
4. A defined tool or successful local flow does not prove hosted deployment, external authorization, side-effect completion, or production traffic. informative

Primary sources