FIELD NOTE / TIKTOK
The guardrail must travel with the work.
The short film, the complete written thought, and the evidence behind it.
The TikTok edition will be linked here after its public post is verified.
The guardrail must travel with the work.
Day 04 · 2026-10-01 · TikTok
Short video caption
A hook passing on your laptop does not prove coverage in a cloud agent. Cursor documents distinct local and cloud hook surfaces. Test a harmless deny in the deployed runtime and keep the action result plus trace. Documentation snapshot, not a live canary. #EricFieldNotes
Full written post / accessible read
Agentic work moves across laptops, editors, command lines and hosted workers. A guardrail can be solid on one surface and absent on another. Cursor gives a concrete example: a local user hook blocks in your laptop test, but that hook does not load in its cloud worker.
The painful part is the false signoff. A policy test passed, but on the wrong runtime. The cloud worker may take an action your laptop would have denied.
Cursor documents the split: local user hooks are unavailable in cloud agent VMs; project hooks load during cloud work; managed hooks exist on Enterprise. The broader lesson is that a control only exists where the worker actually executes it. These are documented surfaces, not my measured cloud results.
Map every execution surface, put policy where its worker loads it, and attempt a harmless forbidden action in each deployed runtime. Retain the result and trace. Do this because a configuration on one machine cannot certify another.
#EricFieldNotes
Evidence and boundary
On-screen boundary: RUNTIME COVERAGE · CURSOR EXAMPLE. The sources below support documented mechanisms and specifications; illustrative scenarios are not presented as measured incidents.