The channel's current tool declarations (GetToolDefinitions()).
The channel's shared tool-name prefix.
Who may invoke these verbs (default 'agent' — native tools are agent tools).
Native tool name to the exposure its RESULT requires, for the tools whose result carries what
the channel holds (see RealtimeChannelVerb.ReturnsChannelData); tools not listed only act.
Builds the verb list for a channel whose actions are its native tools. Both the synthesizer and the reference channels' explicit descriptors use it, so a subclass that adds a tool (an app extending a MJ channel) gets a verb for it automatically instead of a descriptor that lies.