hook up isRequired in parameter info

Author: odrobnik

Sources/SwiftMCP/Models/Tools/MCPToolParameterInfo.swift

@@ -41,13 +41,13 @@ public struct MCPToolParameterInfo: Sendable {
        - defaultValue: An optional default value for the parameter
        - enumValues: The possible values if this is an enum parameter
      */
-    public init(name: String, label: String, type: String, description: String? = nil, defaultValue: Sendable? = nil, enumValues: [String]? = nil) {
+    public init(name: String, label: String, type: String, description: String? = nil, defaultValue: Sendable? = nil, enumValues: [String]? = nil, isRequired: Bool) {
         self.name = name
         self.label = label
         self.type = type
         self.description = description
         self.defaultValue = defaultValue
         self.enumValues = enumValues
-        self.isRequired = defaultValue == nil
+        self.isRequired = isRequired
     }
 } 

Sources/SwiftMCPMacros/MCPToolMacro.swift

@@ -234,7 +234,9 @@ public struct MCPToolMacro: PeerMacro {
 			let enumValuesStr = ".init(caseLabelsFrom: \(paramType).self)"
 
 			// Create parameter info with isRequired property
-			parameterString += "MCPToolParameterInfo(name: \"\(paramName)\", label: \"\(paramLabel)\", type: \"\(paramType)\", description: \(paramDescription), defaultValue: \(defaultValue), enumValues: \(enumValuesStr))"
+			let isOptionalType = paramType.hasSuffix("?") || paramType.hasSuffix("!")
+			let isRequired = defaultValue == "nil" && !isOptionalType
+			parameterString += "MCPToolParameterInfo(name: \"\(paramName)\", label: \"\(paramLabel)\", type: \"\(paramType)\", description: \(paramDescription), defaultValue: \(defaultValue), enumValues: \(enumValuesStr), isRequired: \(isRequired))"
 
 			// Store parameter info for wrapper function generation
 			parameterInfos.append((name: paramName, label: paramLabel, type: paramType, defaultValue: defaultValue))