diff --git a/package-lock.json b/package-lock.json
index 7942d88..7f4f3fd 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@vectorize-io/vectorize-mcp-server",
-  "version": "0.0.1",
+  "version": "0.4.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@vectorize-io/vectorize-mcp-server",
-      "version": "0.0.1",
+      "version": "0.4.0",
       "license": "ISC",
       "dependencies": {
         "@modelcontextprotocol/sdk": "^1.4.1",
diff --git a/package.json b/package.json
index 86828e3..12aeeeb 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@vectorize-io/vectorize-mcp-server",
-  "version": "0.4.0",
+  "version": "0.4.1",
   "description": "MCP server for Vectorize.io.",
   "type": "module",
   "bin": {
diff --git a/src/index.ts b/src/index.ts
index 98d5097..91804ad 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -244,7 +244,7 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
           VECTORIZE_ORG_ID,
           VECTORIZE_PIPELINE_ID,
           args.question + '',
-          Number(args.k)
+          Number(args.k || 4)
         );
       }
       case 'extract': {
@@ -266,18 +266,22 @@ server.setRequestHandler(CallToolRequestSchema, async (request) => {
         throw new Error(`Tool not found: ${name}`);
     }
   } catch (error) {
+    const errorMessage = `Request failed: ${
+      error instanceof Error ? error.message : String(error)
+    }`;
     server.sendLoggingMessage({
       level: 'error',
       data: {
-        message: `Request failed: ${
-          error instanceof Error ? error.message : String(error)
-        }`,
+        message: errorMessage,
         tool: request.params.name,
         arguments: request.params.arguments,
         timestamp: new Date().toISOString(),
       },
     });
-    throw error;
+    return {
+      content: [{ type: 'text', text: JSON.stringify({ error: errorMessage }) }],
+      isError: true,
+    };
   }
 });