feat: Remove 9 low-value tools and consolidate n8n_health_check (v2.25.0)

Telemetry-driven tool cleanup to improve API clarity:

**Removed Tools (9):**
- list_nodes - Use search_nodes instead
- list_ai_tools - Use search_nodes with isAITool filter
- list_tasks - Low usage (0.02%)
- get_database_statistics - Use n8n_health_check
- list_templates - Use search_templates or get_templates_for_task
- get_node_as_tool_info - Documented in get_node
- validate_workflow_connections - Use validate_workflow
- validate_workflow_expressions - Use validate_workflow
- n8n_list_available_tools - Use n8n_health_check
- n8n_diagnostic - Merged into n8n_health_check

**Consolidated Tool:**
- n8n_health_check now supports mode='diagnostic' for detailed troubleshooting

**Tool Count:**
- Before: 38 tools
- After: 31 tools (18% reduction)

Concieved by Romuald Członkowski - www.aiadvisors.pl/en

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/integration/mcp-protocol/protocol-compliance.test.ts

@@ -74,7 +74,7 @@ describe('MCP Protocol Compliance', () => {
       for (let i = 0; i < 5; i++) {
         expectedOrder.push(i);
         requests.push(
-          client.callTool({ name: 'get_database_statistics', arguments: {} })
+          client.callTool({ name: 'tools_documentation', arguments: {} })
             .then(() => i)
         );
       }
@@ -125,7 +125,7 @@ describe('MCP Protocol Compliance', () => {
 
     it('should handle missing params gracefully', async () => {
       // Most tools should work without params
-      const response = await client.callTool({ name: 'list_nodes', arguments: {} });
+      const response = await client.callTool({ name: 'search_nodes', arguments: { query: 'webhook' } });
       expect(response).toBeDefined();
     });
 
@@ -147,8 +147,8 @@ describe('MCP Protocol Compliance', () => {
 
   describe('Content Types', () => {
     it('should handle text content in tool responses', async () => {
-      const response = await client.callTool({ name: 'get_database_statistics', arguments: {} });
-      
+      const response = await client.callTool({ name: 'tools_documentation', arguments: {} });
+
       expect((response as any).content).toHaveLength(1);
       expect((response as any).content[0]).toHaveProperty('type', 'text');
       expect((response as any).content[0]).toHaveProperty('text');
@@ -167,14 +167,15 @@ describe('MCP Protocol Compliance', () => {
     });
 
     it('should handle JSON content properly', async () => {
-      const response = await client.callTool({ name: 'list_nodes', arguments: {
+      const response = await client.callTool({ name: 'search_nodes', arguments: {
+        query: 'webhook',
         limit: 5
       } });
 
       expect((response as any).content).toHaveLength(1);
       const content = JSON.parse((response as any).content[0].text);
-      expect(content).toHaveProperty('nodes');
-      expect(Array.isArray(content.nodes)).toBe(true);
+      expect(content).toHaveProperty('results');
+      expect(Array.isArray(content.results)).toBe(true);
     });
   });
 
@@ -197,10 +198,10 @@ describe('MCP Protocol Compliance', () => {
       const results: string[] = [];
 
       // Start multiple requests with different delays
-      const p1 = client.callTool({ name: 'get_database_statistics', arguments: {} })
-        .then(() => { results.push('stats'); return 'stats'; });
+      const p1 = client.callTool({ name: 'tools_documentation', arguments: {} })
+        .then(() => { results.push('docs'); return 'docs'; });
 
-      const p2 = client.callTool({ name: 'list_nodes', arguments: { limit: 1 } })
+      const p2 = client.callTool({ name: 'search_nodes', arguments: { query: 'webhook', limit: 1 } })
         .then(() => { results.push('nodes'); return 'nodes'; });
 
       const p3 = client.callTool({ name: 'search_nodes', arguments: { query: 'http' } })
@@ -232,13 +233,13 @@ describe('MCP Protocol Compliance', () => {
 
     it('should support optional parameters', async () => {
       // Call with minimal params
-      const response1 = await client.callTool({ name: 'list_nodes', arguments: {} });
-      
+      const response1 = await client.callTool({ name: 'search_nodes', arguments: { query: 'webhook' } });
+
       // Call with all params
-      const response2 = await client.callTool({ name: 'list_nodes', arguments: {
+      const response2 = await client.callTool({ name: 'search_nodes', arguments: {
+        query: 'webhook',
         limit: 10,
-        category: 'trigger',
-        package: 'n8n-nodes-base'
+        mode: 'OR'
       } });
 
       expect(response1).toBeDefined();
@@ -255,7 +256,7 @@ describe('MCP Protocol Compliance', () => {
       await testClient.connect(clientTransport);
 
       // Make a request
-      const response = await testClient.callTool({ name: 'get_database_statistics', arguments: {} });
+      const response = await testClient.callTool({ name: 'tools_documentation', arguments: {} });
       expect(response).toBeDefined();
 
       // Close client
@@ -263,7 +264,7 @@ describe('MCP Protocol Compliance', () => {
 
       // Further requests should fail
       try {
-        await testClient.callTool({ name: 'get_database_statistics', arguments: {} });
+        await testClient.callTool({ name: 'tools_documentation', arguments: {} });
         expect.fail('Should have thrown an error');
       } catch (error) {
         expect(error).toBeDefined();
@@ -286,7 +287,7 @@ describe('MCP Protocol Compliance', () => {
         const testClient = new Client({ name: 'test', version: '1.0.0' }, {});
         await testClient.connect(clientTransport);
 
-        const response = await testClient.callTool({ name: 'get_database_statistics', arguments: {} });
+        const response = await testClient.callTool({ name: 'tools_documentation', arguments: {} });
         expect(response).toBeDefined();
 
         await testClient.close();

tests/unit/mcp/handlers-n8n-manager.test.ts

@@ -1068,14 +1068,14 @@ describe('handlers-n8n-manager', () => {
         },
         toolsAvailability: {
           documentationTools: {
-            count: 22,
+            count: 14,
             enabled: true,
           },
           managementTools: {
-            count: 16,
+            count: 17,
             enabled: true,
           },
-          totalAvailable: 38,
+          totalAvailable: 31,
         },
       });