Prompt injection is a data-plane problem: move the boundary from the model to the tool call.
The author argues that prompt injection shouldn't be solved by making models smarter; instead, just as SQL injection is handled with parameterized queries, the boundary should be drawn where the agent executes actions.
Why it matters: The author draws an analogy between prompt injection and SQL injection, arguing for moving the boundary from the model to the tool-call layer, and lays out a practical approach with a strategy layer and separate read and write phases.