LEARN · AGENT INTEROPERABILITY
Connection is not authority.
MCP connects agents to tools. A2A connects agents to other agents. Neither connection alone answers whether a protected action is permitted.
ONE BOUNDARY
A2A delegates tasks.
VAGP governs delegated authority.
THREE DISTINCT ROLES
Transport, capability and authority have different jobs.
Verimand complements MCP and the external A2A protocol. VAGP is an open authority protocol; Verimand’s public MCP Authority Server is one interface to authority information, while its Authority Gateway is the separately validated enforcement component.
Agent → tools
An agent can discover and call exposed tools. A tool declaration or connection does not create an organisational mandate.
Agent → agent
Agents exchange messages and tasks. An Agent Card describes discovery and capabilities, not delegated VAGP authority.
Authority
An explicit mandate, trusted identity and Agent DNA state determine whether an exact protected action is authorized.
DELEGATED TASK EXAMPLE
A task can arrive without permission to execute it.
Agent A asks Agent B over A2A to restart a sandbox workload. Agent B receives the task and may advertise a relevant skill in its Agent Card. The Gateway still evaluates B’s own trusted identity, Agent DNA and mandate. With no delegated mandate, the protected tool receives no execution. With a valid bounded child mandate, the restart may proceed once.
The same task, two authority states.
A2A task receipt is input to the workflow, never proof of authority. A child mandate may only preserve or narrow its parent’s actions, resources, capabilities, scope and validity. The same rule applies across A → B → C; unrelated paths cannot be combined into broader authority.
Follow permit verification at execution timeVALIDATED BOUNDARY
Task and Agent Card metadata did not bypass authority.
Verimand tested A2A protocol 1.0 task receipt, bounded and multi-hop delegation, amplification, revoked parent authority and replay through a controlled Gateway and protected MCP CloudOps tool. DENY meant zero protected execution in those tests. The public VAGP specification defines attenuation; the validation hub records the narrow integration result.
Inspect A2A validation and limitationsWHAT IS PUBLIC TODAY
The MCP Authority Server is available; the Gateway is distinct.
The public Verimand MCP Authority Server exposes six authority tools for resolution, explanation, inspection and permit verification. Tool availability does not itself grant authority. This server does not intercept protected tool execution. The Authority Gateway has been validated in controlled profiles but is not a public A2A package or a production Gateway release.
Public MCP Registry listingMCP Authority Server sourcePRIMARY SOURCES
Follow each boundary to its own source.
A2A specifies agent communication. VAGP specifies mandate authority. The validation hub distinguishes protocol semantics from what the Verimand integration has actually tested.