Update ToolsTab parameter handling to omit optional empty fields

client/src/App.tsx

@@ -22,6 +22,8 @@ import { SESSION_KEYS, getServerSpecificKey } from "./lib/constants";
 import { AuthDebuggerState, EMPTY_DEBUGGER_STATE } from "./lib/auth-types";
 import { OAuthStateMachine } from "./lib/oauth-state-machine";
 import { cacheToolOutputSchemas } from "./utils/schemaUtils";
+import { cleanParams } from "./utils/paramUtils";
+import type { JsonSchemaType } from "./utils/jsonUtils";
 import React, {
   Suspense,
   useCallback,
@@ -777,12 +779,18 @@ const App = () => {
     lastToolCallOriginTabRef.current = currentTabRef.current;
 
     try {
+      // Find the tool schema to clean parameters properly
+      const tool = tools.find((t) => t.name === name);
+      const cleanedParams = tool?.inputSchema
+        ? cleanParams(params, tool.inputSchema as JsonSchemaType)
+        : params;
+
       const response = await sendMCPRequest(
         {
           method: "tools/call" as const,
           params: {
             name,
-            arguments: params,
+            arguments: cleanedParams,
             _meta: {
               progressToken: progressTokenRef.current++,
             },
@@ -793,6 +801,8 @@ const App = () => {
       );
 
       setToolResult(response);
+      // Clear any validation errors since tool execution completed
+      setErrors((prev) => ({ ...prev, tools: null }));
     } catch (e) {
       const toolResult: CompatibilityCallToolResult = {
         content: [
@@ -804,6 +814,8 @@ const App = () => {
         isError: true,
       };
       setToolResult(toolResult);
+      // Clear validation errors - tool execution errors are shown in ToolResults
+      setErrors((prev) => ({ ...prev, tools: null }));
     }
   };
 

client/src/components/ToolsTab.tsx

@@ -131,14 +131,15 @@ const ToolsTab = ({
             </h3>
           </div>
           <div className="p-4">
-            {error ? (
-              <Alert variant="destructive">
-                <AlertCircle className="h-4 w-4" />
-                <AlertTitle>Error</AlertTitle>
-                <AlertDescription>{error}</AlertDescription>
-              </Alert>
-            ) : selectedTool ? (
+            {selectedTool ? (
               <div className="space-y-4">
+                {error && (
+                  <Alert variant="destructive">
+                    <AlertCircle className="h-4 w-4" />
+                    <AlertTitle>Error</AlertTitle>
+                    <AlertDescription>{error}</AlertDescription>
+                  </Alert>
+                )}
                 <p className="text-sm text-gray-600 dark:text-gray-400">
                   {selectedTool.description}
                 </p>
@@ -184,16 +185,27 @@ const ToolsTab = ({
                             id={key}
                             name={key}
                             placeholder={prop.description}
-                            value={(params[key] as string) ?? ""}
-                            onChange={(e) =>
-                              setParams({
-                                ...params,
-                                [key]:
-                                  e.target.value === ""
-                                    ? undefined
-                                    : e.target.value,
-                              })
+                            value={
+                              params[key] === undefined
+                                ? ""
+                                : String(params[key])
                             }
+                            onChange={(e) => {
+                              const value = e.target.value;
+                              if (value === "") {
+                                // Field cleared - set to undefined
+                                setParams({
+                                  ...params,
+                                  [key]: undefined,
+                                });
+                              } else {
+                                // Field has value - keep as string
+                                setParams({
+                                  ...params,
+                                  [key]: value,
+                                });
+                              }
+                            }}
                             className="mt-1"
                           />
                         ) : prop.type === "object" || prop.type === "array" ? (
@@ -227,13 +239,35 @@ const ToolsTab = ({
                             id={key}
                             name={key}
                             placeholder={prop.description}
-                            value={(params[key] as string) ?? ""}
+                            value={
+                              params[key] === undefined
+                                ? ""
+                                : String(params[key])
+                            }
                             onChange={(e) => {
                               const value = e.target.value;
-                              setParams({
-                                ...params,
-                                [key]: value === "" ? "" : Number(value),
-                              });
+                              if (value === "") {
+                                // Field cleared - set to undefined
+                                setParams({
+                                  ...params,
+                                  [key]: undefined,
+                                });
+                              } else {
+                                // Field has value - try to convert to number, but store input either way
+                                const num = Number(value);
+                                if (!isNaN(num)) {
+                                  setParams({
+                                    ...params,
+                                    [key]: num,
+                                  });
+                                } else {
+                                  // Store invalid input as string - let server validate
+                                  setParams({
+                                    ...params,
+                                    [key]: value,
+                                  });
+                                }
+                              }
                             }}
                             className="mt-1"
                           />

client/src/components/__tests__/ToolsTab.test.tsx

@@ -644,6 +644,7 @@ describe("ToolsTab", () => {
       description: "Tool with JSON parameters",
       inputSchema: {
         type: "object" as const,
+        required: ["config", "data"], // Make them required so they render as form fields
         properties: {
           config: {
             type: "object" as const,
@@ -693,15 +694,16 @@ describe("ToolsTab", () => {
         callTool: mockCallTool,
       });
 
-      // Find JSON editor textareas
+      // Find JSON editor textareas (should have one for each required field: config and data)
       const textareas = screen.getAllByRole("textbox");
+      expect(textareas.length).toBe(2);
 
-      // Enter valid JSON in the first textarea
+      // Enter valid JSON in each textarea
       fireEvent.change(textareas[0], {
-        target: {
-          value:
-            '{ "config": { "setting": "value" }, "data": ["item1", "item2"] }',
-        },
+        target: { value: '{ "setting": "value" }' },
+      });
+      fireEvent.change(textareas[1], {
+        target: { value: '["item1", "item2"]' },
       });
 
       // Wait for debounced updates
@@ -799,9 +801,16 @@ describe("ToolsTab", () => {
       });
 
       const textareas = screen.getAllByRole("textbox");
+      expect(textareas.length).toBe(2);
+
+      // Clear both textareas (empty JSON should be valid)
+      fireEvent.change(textareas[0], { target: { value: "{}" } });
+      fireEvent.change(textareas[1], { target: { value: "[]" } });
 
-      // Clear the textarea (empty JSON should be valid)
-      fireEvent.change(textareas[0], { target: { value: "" } });
+      // Wait for debounced updates
+      await act(async () => {
+        await new Promise((resolve) => setTimeout(resolve, 350));
+      });
 
       // Try to run the tool
       const runButton = screen.getByRole("button", { name: /run tool/i });