Error when creating a new MCP Server

[s4m13337]

I tried creating a new MCP Server using the documentation example:

config = 
 LLMConfiguration[<|"Tools" -> {LLMTool[
      "PrimeFinder", {"n" -> "Integer"}, Prime[#n] &]}|>];

server = 
 CreateMCPServer["Wolfram Language Evaluator", config, 
  OverwriteTarget -> True]

It fails with some unexpected error message.

https://github.com/rhennigan/MCPServer/blob/a0c26f8c9d977b665f5f3db82836f3cedb2dc1b8/Kernel/CreateMCPServer.wl#L72-L72

Debug Data

Property	Value
Name	"RickHennigan/MCPServer"
Version	"1.3.0"
ReleaseID	"a0c26f8c9d977b665f5f3db82836f3cedb2dc1b8"
EvaluationEnvironment	"Session"
FrontEndVersion	"Desktop: 14.3 for Mac OS X ARM (64-bit) (July 8, 2025)"
KernelVersion	"14.3.0 for Mac OS X ARM (64-bit) (July 8, 2025)"
SystemID	"MacOSX-ARM64"
Notebooks	True
DynamicEvaluation	False
SynchronousEvaluation	False
TaskEvaluation	False

Settings

Property	Value

Failure Data

<|
  "Evaluation" :> RickHennigan`MCPServer`CreateMCPServer`Private`createMCPServer["Wolfram Language Evaluator", <|"Model" -> Automatic, "MaxTokens" -> Automatic, "Temperature" -> Automatic, "TotalProbabilityCutoff" -> Automatic, "Prompts" -> Automatic, "PromptDelimiter" -> Automatic, "StopTokens" -> Automatic, "ToolMethod" -> Automatic, "Tools" -> {LLMTool[<|"Name" -> "PrimeFinder", "Description" -> "", "Parameters" -> {"n" -> <|"Interpreter" -> "Integer", "Help" -> Missing["NotSpecified"], "Required" -> True|>}, ...,
  "Information" -> "ExportCheck@@Kernel/CreateMCPServer.wl:72,9-72,82",
  "ConfirmationType" -> "ConfirmAssert",
  "Expression" :> False,
  "Test" :> False,
  "Stack" :> RickHennigan`MCPServer`Common`Private`$stack$19459,
  "Failure" -> Failure["ConfirmationFailed", <|"MessageTemplate" -> "ExportCheck@@Kernel/CreateMCPServer.wl:72,9-72,82", "MessageParameters" -> {}, "HeldTest" -> Hold[Developer`ReadWXFFile[RickHennigan`MCPServer`CreateMCPServer`Private`exported$19437] === RickHennigan`MCPServer`CreateMCPServer`Private`data$19437], "ConfirmationType" -> "ConfirmAssert", "Expression" :> False, "Information" -> "ExportCheck@@Kernel/CreateMCPServer.wl:72,9-72,82", "Test" :> False|>],
  "Arguments" -> {}
|>

Stack Data

trimURL
throwFailure
catchTop