Handle MCP tools addition as an update operation when the connection already exists

If MCP tools are added for an already configured connection, treat it similarly to an update operation.

Author: chathuranga-jayanath-99

org.eclipse.lemminx/src/main/java/org/eclipse/lemminx/customservice/synapse/mediatorService/AIConnectorHandler.java

@@ -387,7 +387,7 @@ private SynapseConfigResponse addAIAgentTool(String documentUri, Range range, St
             DOMNode mcpMediatorNode = node.getParentNode();
 
             // Build updated <tools> XML
-            String updatedToolsXml = buildMergedToolsXml(document, node, connectionName, mcpToolsSelection);
+            String updatedToolsXml = buildUpdatedToolsXml(document, node, connectionName, mcpToolsSelection);
             TextEdit edit = createToolsTextEdit(document, node, mcpMediatorNode, updatedToolsXml, documentUri);
             agentEditResponse.addTextEdit(edit);
 
@@ -1117,46 +1117,6 @@ private SynapseConfigResponse modifyAgentTool(String documentUri, Range range, S
         return agentEditResponse;
     }
 
-    /**
-     * Builds a merged `<tools>` XML fragment by preserving existing tool entries and adding new tools
-     * for the specified MCP connection.
-     *
-     * <p>For each existing tool node, the original XML is preserved. If an existing tool belongs to the
-     * `targetConnection`, its name is recorded so duplicates are not added. Any tool name present in
-     * `selectedTools` but not already present for the `targetConnection` will be created and appended.</p>
-     *
-     * @param document         the DOMDocument representing the current XML document (used to extract existing tool XML)
-     * @param toolsNode        the DOMNode representing the parent `<tools>` element; may be null
-     * @param targetConnection the name of the MCP connection to which selected tools should be associated
-     * @param selectedTools    list of MCP tools selected, each represented as a map with a "name" key and  a
-     *                         "description" key
-     * @return the rendered XML string for the merged `<tools>` block
-     */
-    private String buildMergedToolsXml(DOMDocument document, DOMNode toolsNode, String targetConnection,
-                                       List<Map<String, Object>> selectedTools) {
-
-        List<ExistingTool> existingTools = extractExistingTools(document, toolsNode);
-        List<String> finalXMLs = new ArrayList<>();
-        Set<String> existingNamesForConnection = new HashSet<>();
-
-        for (ExistingTool tool : existingTools) {
-            finalXMLs.add(tool.xml);
-            if (targetConnection.equals(tool.connection)) {
-                existingNamesForConnection.add(tool.name);
-            }
-        }
-
-        for (Map<String, Object> toolMap : selectedTools) {
-            String toolName = (String) toolMap.get(Constant.NAME);
-            String toolDescription = (String) toolMap.get(Constant.DESCRIPTION);
-            if (!existingNamesForConnection.contains(toolName)) {
-                String newToolXml = createNewMCPToolXml(toolName, toolDescription, targetConnection);
-                finalXMLs.add(newToolXml.stripTrailing());
-            }
-        }
-        return generateToolsXmlFromStrings(finalXMLs);
-    }
-
     /**
      * Builds an updated `<tools>` XML fragment for the MCP agent.
      * <p>