diff --git a/src/MCP-Tests/MCPToolMethodMutationTest.class.st b/src/MCP-Tests/MCPToolMethodMutationTest.class.st
index 08a02e5..9563cb1 100644
--- a/src/MCP-Tests/MCPToolMethodMutationTest.class.st
+++ b/src/MCP-Tests/MCPToolMethodMutationTest.class.st
@@ -928,8 +928,10 @@ MCPToolMethodMutationTest >> testCompileReturnsStructuredCommandErrorForSyntaxEr
 	self assert: (error at: #errorCode) equals: 'CompileSyntaxError'.
 	self assert: (error at: #className) equals: MCPToolMethodMutationTestTarget name.
 	self assert: (error at: #classSide) equals: false.
-	self assert: (error at: #protocol) equals: 'tests'.
-	self assert: (error includesKey: #position).
+	self assert: (error at: #position) equals: 19.
+	self assert: (error at: #line) equals: 1.
+	self assert: (error at: #column) equals: 19.
+	self assert: (error at: #sourceLine) equals: 'brokenMethod ^ 1 +'.
 	self deny: (error includesKey: #variableName).
 	self deny: (MCPToolMethodMutationTestTarget includesSelector: #brokenMethod)
 ]
@@ -954,10 +956,12 @@ MCPToolMethodMutationTest >> testCompileReturnsStructuredCommandErrorForUndeclar
 	self assert: (self expectedUndeclaredVariableNoticeClassNames includes: (error at: #causeClass)).
 	self assert: (error at: #className) equals: MCPToolMethodMutationTestTarget name.
 	self assert: (error at: #classSide) equals: false.
-	self assert: (error at: #protocol) equals: 'tests'.
 	self assert: (error at: #selector) equals: 'brokenMethod'.
 	self assert: (error at: #variableName) equals: 'missingVar'.
 	self assert: (error at: #position) equals: 16.
+	self assert: (error at: #line) equals: 1.
+	self assert: (error at: #column) equals: 16.
+	self assert: (error at: #sourceLine) equals: 'brokenMethod ^ missingVar'.
 	self assert: ((error at: #message) includesSubstring: 'missingVar').
 	self deny: (MCPToolMethodMutationTestTarget includesSelector: #brokenMethod)
 ]
diff --git a/src/MCP/MCPCompileMethodCommand.class.st b/src/MCP/MCPCompileMethodCommand.class.st
index 3acaec3..46b0800 100644
--- a/src/MCP/MCPCompileMethodCommand.class.st
+++ b/src/MCP/MCPCompileMethodCommand.class.st
@@ -30,11 +30,15 @@ MCPCompileMethodCommand >> execute [
 		  work: [
 				  behavior := self tool behaviorNamed: self request className classSide: self request classSide.
 				  methodSource := self request methodSource withInternalLineEndings.
-				  selector := self selectorForMethodSource: methodSource.
+				  selector := [ self selectorForMethodSource: methodSource ]
+					              on: Exception
+					              do: [ :error | self signalCompileFailure: error methodSource: methodSource ].
 				  changeKind := (behavior includesSelector: selector)
 					                ifTrue: [ 'replaced' ]
 					                ifFalse: [ 'created' ].
-				  selector := behavior compile: methodSource classified: self request protocol.
+				  selector := [ behavior compile: methodSource classified: self request protocol ]
+					              on: Exception
+					              do: [ :error | self signalCompileFailure: error methodSource: methodSource ].
 				  compiledMethod := self tool reformattedMethodForBehavior: behavior selector: selector.
 				  methodReference := self tool methodReferenceForBehavior: behavior selector: selector.
 				  result := MCPMethodCompileResult
@@ -58,3 +62,16 @@ MCPCompileMethodCommand >> selectorForMethodSource: methodSourceString [
 	self tool signalBlockingCritiquesForMethodNode: methodNode.
 	^ methodNode selector
 ]
+
+{ #category : 'private - errors' }
+MCPCompileMethodCommand >> signalCompileFailure: anError methodSource: methodSource [
+
+	anError mcpCommandErrorDo: [ :commandError | commandError signal ] otherwise: [ :compileError |
+			(self tool
+				 commandErrorForCompileFailure: compileError
+				 methodSource: methodSource
+				 requestedContext: self request requestedContext
+				 summary:
+				 (self tool failureMessageForCompileClassNamed: self request className classSide: self request classSide error: compileError))
+				signal ]
+]
diff --git a/src/MCP/MCPMethodCompileRequest.class.st b/src/MCP/MCPMethodCompileRequest.class.st
index 54a52c0..447d99e 100644
--- a/src/MCP/MCPMethodCompileRequest.class.st
+++ b/src/MCP/MCPMethodCompileRequest.class.st
@@ -79,6 +79,5 @@ MCPMethodCompileRequest >> requestedContext [
 
 	^ {
 		  (#className -> self className).
-		  (#classSide -> self classSide).
-		  (#protocol -> self protocol) } asDictionary
+		  (#classSide -> self classSide) } asDictionary
 ]
diff --git a/src/MCP/MCPToolMethodMutation.class.st b/src/MCP/MCPToolMethodMutation.class.st
index 91efb4d..197d8ab 100644
--- a/src/MCP/MCPToolMethodMutation.class.st
+++ b/src/MCP/MCPToolMethodMutation.class.st
@@ -25,6 +25,12 @@ MCPToolMethodMutation class >> isAbstract [
 	^ self = MCPToolMethodMutation
 ]
 
+{ #category : 'private - errors' }
+MCPToolMethodMutation >> addCompileSourceContextFor: methodSource to: details [
+
+	details at: #position ifPresent: [ :position | self addSourceLineContextFor: methodSource position: position to: details ]
+]
+
 { #category : 'private - refactoring' }
 MCPToolMethodMutation >> addParameterRefactoringForSelector: oldSelectorSymbol inBehavior: aBehavior to: newSelectorSymbol permutation: permutation newArgs: newArguments model: refactoringModel [
 
@@ -37,6 +43,24 @@ MCPToolMethodMutation >> addParameterRefactoringForSelector: oldSelectorSymbol i
 		  newArgs: newArguments
 ]
 
+{ #category : 'private - errors' }
+MCPToolMethodMutation >> addSourceLineContextFor: methodSource position: position to: details [
+
+	| boundedPosition column lineEnd lineNumber lineStart sourceLine sourceText |
+	sourceText := methodSource ifNil: [ '' ] ifNotNil: [ methodSource asString ].
+	sourceText isEmpty ifTrue: [ ^ self ].
+	boundedPosition := (position max: 1) min: sourceText size + 1.
+	lineStart := sourceText lastIndexOf: Character cr startingAt: boundedPosition - 1 ifAbsent: [ 0 ].
+	lineEnd := sourceText indexOf: Character cr startingAt: boundedPosition ifAbsent: [ sourceText size + 1 ].
+	lineNumber := (sourceText copyFrom: 1 to: lineStart) occurrencesOf: Character cr.
+	column := boundedPosition - lineStart.
+	sourceLine := sourceText copyFrom: lineStart + 1 to: lineEnd - 1.
+	details
+		at: #line put: lineNumber + 1;
+		at: #column put: column;
+		at: #sourceLine put: sourceLine
+]
+
 { #category : 'metadata' }
 MCPToolMethodMutation >> additionalKeywords [
 
@@ -104,6 +128,19 @@ MCPToolMethodMutation >> classReferenceNameFor: className classSide: classSide [
 		  ifFalse: [ className ]
 ]
 
+{ #category : 'private - errors' }
+MCPToolMethodMutation >> commandErrorForCompileFailure: anError methodSource: methodSource requestedContext: requestedContext summary: summary [
+
+	| commandError |
+	commandError := self
+		                normalizedCommandErrorForActionFailure: anError
+		                action: 'compile'
+		                requestedContext: requestedContext
+		                summary: summary.
+	self addCompileSourceContextFor: methodSource to: commandError details.
+	^ commandError
+]
+
 { #category : 'private' }
 MCPToolMethodMutation >> critiqueDataFor: aCritique [