Giving an AI agent the keys without giving it the building: RBAC + org-scoped MCP tools in Laravel

Exposing your app to an AI agent over MCP is basically handing someone a master keyring and trusting them to only open the doors they're supposed to. That trust is a bug waiting to happen. This week I wired up a batch of MCP tools over a multi-tenant Laravel app, and the whole exercise was really about one question: how do I let an agent drive the app without letting it drive someone else's data? Here's the thing about MCP tools — each one is an endpoint. An agent calls list_events , publish_event , check_in_participant , and your server runs code on the caller's behalf. The moment you have more than one tenant, every single tool needs to answer two questions before it does anything: are you allowed to do this , and are you allowed to do it *here *. Authorization and scope. Skip either and you've built a confused deputy. The trap: ambient scope doesn't exist under token auth In a normal web request, multi-tenancy is comfortable. You've got a logged-in user, a global scope on the model that quietly appends where organization_id = ? , and you mostly forget it's there. Everything Just Works because there's an ambient "current organization" sitting in the session. MCP tools don't have that. The caller authenticates with a token, there's no session, no middleware stack that set up a current-tenant context. If you lean on a global OrganizationScope that reads "the current org" from somewhere, it reads nothing — and a query you assumed was fenced returns every tenant's rows. That's the kind of bug that doesn't throw an error; it just silently leaks. So the rule I settled on: under token auth, never rely on ambient scope. Filter explicitly, every time, in one place. That "one place" is a small trait every event-scoped tool pulls in: trait ResolvesOrgEvents { protected function resolveOrgEvent ( Authenticatable $user , string $uuid ): ?Event { if ( empty ( $user -> organization_id )) { return null ; } return Event :: query () -> withOrganization ( $user -> organization_id )