A shared room is not shared authority
Aviation maintenance organizations may operate from shared physical stores while tools remain owned, governed, or restricted by different companies.
A credible tool-control system needs separate concepts for physical location, ownership, operational availability, and permission to issue.
Scope belongs in services and repositories
Company and tenant isolation cannot be a UI-only filter. The lower layers that load and mutate tool data must enforce scope before a screen ever renders.
That design choice matters for trust: audit trails are only useful when the wrong organization cannot see or alter the wrong record.
Cross-company loans need evidence
Where cross-company use is allowed, the system should record the approving context, issuing actor, receiving holder, timing, and return evidence.
The landing site should describe that capability as operational evidence, not as a promise that the software makes airworthiness decisions.