Every integration an organization stops building is one it starts depending on.
Google published Agent Tools & Interoperability in May 2026, a practitioner guide to five open protocols: MCP for tools, A2A for agent-to-agent work, A2UI for generated interfaces, and AP2 and UCP for commerce.
What it says
Its stated priority is consumption over creation. Pull pre-built servers from public or internal registries. Hire official specialist agents rather than maintain custom ones. Map to a component catalog rather than write interface code. Procure agents from a marketplace. The reasoning is cost: bespoke integration carries what the paper calls a maintenance tax.
Security guidance is present and mostly advisory. Audit public servers, avoid hardcoded credentials, do not connect to production, scope access to one project. One control is structural. A2UI restricts agents to components the renderer already trusts, so a generated interface cannot carry executable code regardless of what the model produced.
Why it matters
Each consumption decision moves a dependency outside the perimeter. Accountability for the outcome stays inside it.
These dependencies do not resemble AI assets. A remote agent resolved by name, a tool server, a component catalog, a marketplace listing: none of them register in an inventory built around models.
The paper defines an Agent Card, a machine-readable identity declaring capabilities, interaction schemas, and data handling policies. It is published by the agent and read at discovery time. Third-party posture arrives as an assertion, at machine speed.
Key takeaways
- An AI inventory that stops at the model layer misses most of what an agent stack actually runs on.
- Self-declared vendor descriptions consumed automatically at runtime are an input to third-party risk, not a replacement for assessment.
- Controls enforced by the receiving system hold. Controls that depend on operator discipline decay.
Source:
· Google — Agent Tools & Interoperability — kaggle.com, May 2026
Which layer of an agent stack could your organization name today: the tools, the remote agents, the interface catalog, or the payment path?