MCP call tool

Tag 3: the server relays an MCP `tools/call` exchange a program in the container asked of the caller’s MCP servers, its params as the program sent them; the client answers with exactly one channel response, the result or the MCP error, which the server relays to the program.

The server opens this channel when a program in the container asks for one tool of the MCP servers of the caller, called. The params are sent as the program sent them; the client’s one answer is relayed back.

• The request. The tag byte 3 followed by the params of the MCP method tools/call as JSON. Request states its form.
• The response. Exactly one channel response, the result or an error, and the channel response finish. Response states the sequence.
• No repetition. The server sends the exchange exactly once. A channel that ends without a finish is not asked again.
• The meaning. What the exchange is, MCP call tool states.