RegisteredTool.requiredClientCapabilities

Client capabilities this tool's handler requires to run. On the draft protocol, tools/call rejects with a -32003 MissingRequiredClientCapabilityError (whose data.requiredCapabilities lists the unmet ones) when the request's declared client capabilities do not cover these. Empty (the default) means no gating.

struct RegisteredTool
ClientCapabilities requiredClientCapabilities;