Topic starter
20/01/2026 12:57 pm
TL;DR: MCP standardises LLM-to-tool access while A2A standardises agent-to-agent collaboration, and Descope argues the two protocols work best together rather than as competitors. The identity problem is not the protocol choice itself, but the authentication, least privilege, and monitoring model wrapped around expanding agent surfaces.
Editorial analysis by NHI Mgmt Group, based on content published by Descope: “A2A vs. MCP”.
Key questions
Q: How should teams secure MCP and A2A deployments without over-scoping access?
A: Start by separating tool access from agent-to-agent delegation and assign each path its own authorization policy.
Q: Why do MCP and A2A increase identity risk even when the protocols are standardised?
A: Because standardisation reduces integration friction, not trust complexity.
Q: What breaks when agent capability discovery is not tightly governed?
A: Capability discovery can expose more authority than teams realise, especially when agent descriptors advertise actions that are not aligned to current policy.
Practitioner guidance
- Define separate trust policies for MCP and A2A Map which identities may request tools through MCP and which may delegate tasks through A2A, then give each path its own authorization scope and review cadence.
- Inventory every agent-capability publication point Track where Agent Cards, capability registries, or similar descriptors expose what an agent can do, and ensure those claims match approved access boundaries.
- Enforce least privilege at the protocol edge Limit each agent or LLM to the narrowest tool set, dataset, or peer-agent action set required for the task, and avoid broad standing access.
Bottom line: MCP and A2A are not competing integration choices so much as two different expansion points for AI identity governance.
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This topic was modified 7 days ago by NHI Mgmt Group
06/10/2026 6:44 pm
MCP and A2A are complementary protocols, but they also multiply the places where identity must be enforced. MCP governs tool access, while A2A governs agent collaboration, so the security burden shifts to the controls wrapped around each hop. The practitioner mistake is to treat protocol standardisation as a substitute for authorization design. The right conclusion is that identity governance now spans both vertical tool access and horizontal agent delegation.
A few things that frame the scale:
- 24,008 unique secrets were exposed in MCP configuration files in 2025 alone, the protocol's first year of widespread adoption, according to the State of Secrets Sprawl 2026.
- Only 13% of organisations feel extremely prepared for the reality of agentic AI despite the majority racing toward autonomous adoption, according to the 2026 Infrastructure Identity Survey.
A question worth separating out:
Q: What should security teams do immediately when cross-agent delegation starts to scale?
A: Instrument the delegation chain before broad rollout. Capture task origin, target agent, scope granted, and completion status, then verify that monitoring can detect anomalous delegation, denied requests, and unexpected peer-to-peer activity across the workflow.
👉 Read our full editorial: MCP and A2A are complementary, but identity controls must catch up