removed unnecessary file

Author: odrobnik

Sources/SwiftMCPMacros/MCPDiagnostics.swift

@@ -29,6 +29,9 @@ enum MCPToolDiagnostic: DiagnosticMessage {
 
     /// Error when a parameter has an unsupported closure type
     case closureTypeNotSupported(paramName: String, typeName: String)
+    
+    /// Error when an optional parameter is missing a default value
+    case optionalParameterNeedsDefault(paramName: String, typeName: String)
 
     var message: String {
         switch self {
@@ -40,18 +43,20 @@ enum MCPToolDiagnostic: DiagnosticMessage {
             return "Parameter '\(paramName)' has an unsupported default value type '\(typeName)'. Only numbers, booleans, and strings are supported."
         case .closureTypeNotSupported(let paramName, let typeName):
             return "Parameter '\(paramName)' has an unsupported closure type '\(typeName)'. Closures are not supported in MCP tools."
+        case .optionalParameterNeedsDefault(let paramName, let typeName):
+            return "Optional parameter '\(paramName)' of type '\(typeName)' requires a default value (e.g. = nil)."
         }
     }
 
     var severity: DiagnosticSeverity {
         switch self {
-        case .onlyFunctions, .invalidDefaultValueType, .closureTypeNotSupported:
+        case .onlyFunctions, .invalidDefaultValueType, .closureTypeNotSupported, .optionalParameterNeedsDefault:
             return .error
         case .missingDescription:
             return .warning
         }
     }
-
+    
     var diagnosticID: MessageID {
         switch self {
         case .onlyFunctions:
@@ -62,6 +67,33 @@ enum MCPToolDiagnostic: DiagnosticMessage {
             return MessageID(domain: "SwiftMCP", id: "invalidDefaultValueType")
         case .closureTypeNotSupported:
             return MessageID(domain: "SwiftMCP", id: "closureTypeNotSupported")
+        case .optionalParameterNeedsDefault:
+            return MessageID(domain: "SwiftMCP", id: "optionalParameterNeedsDefault")
+        }
+    }
+}
+
+enum MCPToolFixItMessage: FixItMessage {
+    case addDefaultValue(paramName: String)
+    
+    var message: String {
+        switch self {
+        case .addDefaultValue(let paramName):
+            return "Add default value '= nil' for parameter '\(paramName)'"
+        }
+    }
+    
+    var diagnosticID: MessageID {
+        switch self {
+        case .addDefaultValue:
+            return MessageID(domain: "SwiftMCP", id: "addDefaultValue")
+        }
+    }
+    
+    var fixItID: MessageID {
+        switch self {
+        case .addDefaultValue:
+            return MessageID(domain: "SwiftMCP", id: "addDefaultValue")
         }
     }
 } 

Sources/SwiftMCPMacros/MCPToolMacro.swift

@@ -155,6 +155,37 @@ public struct MCPToolMacro: PeerMacro {
 				context.diagnose(diagnostic)
 			}
 
+			// Check for optional parameters without default values
+			let isOptional = param.type.is(OptionalTypeSyntax.self) || 
+							param.type.is(ImplicitlyUnwrappedOptionalTypeSyntax.self) ||
+							paramType.hasSuffix("?") ||
+							paramType.hasSuffix("!")
+			
+			if isOptional && param.defaultValue == nil {
+				let diagnostic = Diagnostic(
+					node: param.type,
+					message: MCPToolDiagnostic.optionalParameterNeedsDefault(
+						paramName: paramName,
+						typeName: paramType
+					),
+					fixIts: [
+						FixIt(
+							message: MCPToolFixItMessage.addDefaultValue(paramName: paramName),
+							changes: [
+								.replace(
+									oldNode: Syntax(param),
+									newNode: Syntax(param.with(\.defaultValue, InitializerClauseSyntax(
+										equal: TokenSyntax.equalToken(leadingTrivia: .spaces(1), trailingTrivia: .spaces(1)),
+										value: ExprSyntax(NilLiteralExprSyntax())
+									)))
+								)
+							]
+						)
+					]
+				)
+				context.diagnose(diagnostic)
+			}
+			
 			// Store parameter info for wrapper function generation
 
 			// Special case for the longDescription function's text parameter in tests