Fix: Correct resource fallback tool detection logic

The previous logic incorrectly checked clientCapabilities.resources which
doesn't exist (resources is a SERVER capability, not a CLIENT capability).

Now correctly detects clients by name using getClientVersion() and only
registers fallback tools for clients with known resource support issues
(e.g., Claude Desktop).

Result: MCP Inspector and other proper clients now see 24 tools instead
of 26, with resource fallback tools only appearing for Claude clients.

Fixes dynamic tool registration to work as intended.

Author: mattpodwysocki

src/index.ts

@@ -226,6 +226,13 @@ async function main() {
 
   // After connection, dynamically register capability-dependent tools
   const clientCapabilities = server.server.getClientCapabilities();
+
+  // Debug: Log what capabilities we detected
+  server.server.sendLoggingMessage({
+    level: 'info',
+    data: `Client capabilities detected: ${JSON.stringify(clientCapabilities, null, 2)}`
+  });
+
   let toolsAdded = false;
 
   // Register elicitation tools if client supports elicitation
@@ -246,14 +253,20 @@ async function main() {
     });
   }
 
-  // Register resource fallback tools if client doesn't properly support resources
-  // Note: GetReferenceTool exists as a workaround for Claude Desktop which lists resources
-  // but doesn't automatically fetch them. Most modern clients support resources properly.
-  const supportsResources = clientCapabilities?.resources !== undefined;
-  if (!supportsResources && enabledResourceFallbackTools.length > 0) {
+  // Register resource fallback tools for clients with known resource support issues
+  // Note: Resources are a core MCP feature, but some clients (like Claude Desktop) can list
+  // resources but don't automatically fetch them. We detect these clients by name.
+  // Most modern MCP clients (Inspector, VS Code, etc.) support resources properly.
+  const clientVersion = server.server.getClientVersion();
+  const clientName = clientVersion?.name?.toLowerCase() || '';
+
+  // Known clients with resource support issues
+  const needsResourceFallback = clientName.includes('claude');
+
+  if (needsResourceFallback && enabledResourceFallbackTools.length > 0) {
     server.server.sendLoggingMessage({
       level: 'info',
-      data: `Client lacks full resource support. Registering ${enabledResourceFallbackTools.length} resource fallback tools`
+      data: `Client "${clientVersion?.name}" has known resource issues. Registering ${enabledResourceFallbackTools.length} resource fallback tools`
     });
 
     enabledResourceFallbackTools.forEach((tool) => {
@@ -263,7 +276,7 @@ async function main() {
   } else if (enabledResourceFallbackTools.length > 0) {
     server.server.sendLoggingMessage({
       level: 'debug',
-      data: `Client supports resources properly. Skipping ${enabledResourceFallbackTools.length} resource fallback tools`
+      data: `Client "${clientVersion?.name}" supports resources properly. Skipping ${enabledResourceFallbackTools.length} resource fallback tools`
     });
   }