Address review comments on tool conflict resolution

- Add nil check in tool_adapter.go to prevent panic when tool not found in originalToolsByName map
- Add comment explaining O(n²) complexity is acceptable for small tool lists
- Improve warning message when priority strategy drops tools from backends not in priority list
- Show which backends were involved when dropping conflicting tools

Co-authored-by: Juan Antonio Osorio <JAORMX@users.noreply.github.com>

Author: github-actions[bot]

pkg/mcp/tool_filter.go

@@ -508,6 +508,10 @@ func processToolsListResponse(
 	processedTools := applyFilteringAndOverrides(config, simpleTools)
 
 	// Build the filtered response by matching processed tools with their original maps
+	// Note: This is O(n²) complexity, but acceptable because:
+	// - Tool lists are typically small (< 100 tools per backend)
+	// - Only runs once during tool list retrieval (not in hot path)
+	// - Inner loop breaks early on match
 	filteredTools := make([]map[string]any, 0, len(processedTools))
 	for _, processed := range processedTools {
 		// Find the original tool map by matching names

pkg/vmcp/aggregator/conflict_resolver.go

@@ -163,8 +163,13 @@ func (r *PriorityConflictResolver) ResolveToolConflicts(
 		// Conflict detected - choose the highest priority backend
 		winner := r.selectWinner(candidates)
 		if winner == nil {
-			// All candidates are from backends not in priority list
-			logger.Warnf("Tool %s exists in multiple backends but none are in priority order, skipping", toolName)
+			// All candidates are from backends not in priority list - drop all of them
+			// This is intentional: priority strategy requires explicit priority ordering
+			backendIDs := make([]string, len(candidates))
+			for i, c := range candidates {
+				backendIDs[i] = c.BackendID
+			}
+			logger.Warnf("Tool %s exists in multiple backends %v but none are in priority order, dropping all instances", toolName, backendIDs)
 			droppedTools += len(candidates)
 			continue
 		}

pkg/vmcp/aggregator/tool_adapter.go

@@ -74,24 +74,30 @@ func processBackendTools(
 	}
 
 	// Convert back to vmcp.Tool, preserving InputSchema and BackendID
-	result := make([]vmcp.Tool, len(processed))
-	for i, simpleTool := range processed {
+	result := make([]vmcp.Tool, 0, len(processed))
+	for _, simpleTool := range processed {
 		// Find the original tool name (before any override)
 		originalName := simpleTool.Name
 		if revName, wasOverridden := reverseOverrideMap[simpleTool.Name]; wasOverridden {
 			originalName = revName
 		}
 
 		// Look up the original tool to preserve InputSchema and BackendID
-		originalTool := originalToolsByName[originalName]
+		originalTool, exists := originalToolsByName[originalName]
+		if !exists {
+			// This should not happen unless there's a bug in the filtering logic,
+			// but skip the tool rather than panicking
+			logger.Warnf("Tool %s not found in original tools map for backend %s, skipping", originalName, backendID)
+			continue
+		}
 
 		// Construct the result tool with processed name/description but original schema
-		result[i] = vmcp.Tool{
+		result = append(result, vmcp.Tool{
 			Name:        simpleTool.Name,        // Use the processed (potentially overridden) name
 			Description: simpleTool.Description, // Use the processed (potentially overridden) description
 			InputSchema: originalTool.InputSchema,
 			BackendID:   backendID, // Use the backendID parameter (source of truth)
-		}
+		})
 	}
 
 	return result