Why does Agents → All agents suddenly show a hundred entries?

That’s a genuine concern, and you’re not imagining the jump. The inventory is doing its job — surfacing Microsoft, partner, org-published, and shared agents in one place — which feels like sprawl the first time you open it.

Here’s what’s going on. In Microsoft 365 admin centre, Agents → All agents is the organisational inventory: filter by Availability (all users / no users), spot Missing an owner, and open each agent for publisher, support surfaces, and assignment. Registry types include Microsoft agents, external partner-built, published by your org, and shared by creator. Tenant-wide Agent settings matter more than scrolling forever: Allowed agent types lets you separately allow apps/agents built by Microsoft, by your organisation, and by external publishers — turn external off and those agents no longer appear for users in the Agent store (Microsoft agents may still be visible but not installable if that toggle is off). User access can be All users, No users, or Specific users/groups. Per agent you can Block / Unblock for the organisation, set Available to / Deployed to (just me, entire org, or specific users/groups), and reassign owners. Learn is blunt on third parties: data processed by non-Microsoft services isn’t under Microsoft agreements — review publisher terms before you allow external.

This is Third Law for organisational AI: the easier it is for everyone to install an agent, the easier it is for everyone (and every vendor) to reach your work data through that agent. Steady before scale means Pane 04 Security sets Allowed types and a short allow-list before Agent Store becomes a free-for-all.

Options that actually work:

1. External publishers off by default; allow-list by name. Disable Allow apps and agents built by external publishers, then Unblock / Deploy only the one or two you actually need to specific groups. Best Steady default.
2. Keep types on; tighten User access + per-agent Block. Useful while you inventory; still leaves the store noisy. Pair with a weekly review of Availability → All users.
3. Block everything including Microsoft agents. Possible for some built-ins only via Block (e.g. Researcher/Analyst aren’t granular-assignable) — heavy-handed if you still want Copilot’s first-party skills.
4. Ignore the inventory until Finance asks. Quiet until a user installs a partner agent that ships prompts off-tenant. I’d avoid this.

12 Panes action / comms: Screenshot today’s count by type for leadership. Message: visibility isn’t permission — Allowed agent types is the gate. Tell service owners which external agents are approved and who can install them.

Benefits / risks: Inventory + Allowed types give you a real control plane without deleting useful Microsoft agents. Blocking a SharePoint- or Foundry-built agent may mainly remove it from Copilot Chat, not every host surface — read the platform note before you promise “gone everywhere.” Ownerless shared agents still need the reclaim path we covered separately.

I’d suggest this week: set Allowed agent types to Microsoft + your org only, Block anything external that isn’t on the approved list, then Deploy the exceptions to named groups. You’ll sleep better when the inventory is long but the installable set is short.

DIGITAL SKILL WORKS LTD / 12 PANES · You ask, we answer