Standardised Inter-Agent Protocol
Use open, interoperable protocols (Agent-to-Agent / A2A, Model Context Protocol / MCP) for communication between agents and between agents and tools, not bespoke glue.
This page is the complete instruction page for one pattern called "Standardised Inter-Agent Protocol." It explains the problem this pattern solves, the idea behind the solution, when you should (and should not) use it, and what happens afterward, both the good effects and the costs.
This matters because building AI agents is not just about making them clever. It is also about making them safe and predictable. Following a well-tested pattern like this one helps avoid common mistakes, and shows you exactly which safety rules and regulations it connects to, listed under "Standards Mesh" on this page.
Context
Multi-agent systems proliferate with each team building its own wire format. Integration cost dominates; portability is zero.
Problem
Proprietary protocols create lock-in and N-squared integration work.
Forces
- Vendor feature velocity vs interoperability
- Protocol richness vs adoption friction
Solution
Adopt A2A (agent-to-agent messaging) and MCP (model context protocol for tools and data sources) as the default wire formats. Bespoke protocols only where no standard exists. Declare protocol version and capabilities at handshake.
Where this pattern acts in the two lifecycles
03 Decide. Tool / route / next-action selection. 7 of 61 catalogue patterns act at this stage.
02 Build & Integrate. Model selection, tool wiring, memory design. 17 of 61 catalogue patterns act at this stage.
Stages and counts from the catalogue data. The Runtime lens is the loop the agent runs each turn; the AgentOps lens is the lifecycle the team runs the agent through. See the Matrix for every pattern at each stage.
Applicability
- Multi-agent platforms
- Cross-vendor agent ecosystems
- Any agent expecting to call or be called by external agents
Anti-Patterns
- Custom JSON-over-HTTP for every integration
- Implicit contracts without versioning
Consequences
- +Portability across platforms
- +Ecosystem tool reuse
- −Standards are young and evolving
- −Some features not yet in standard
