Update tool name validation to support dots, slashes, and 128-char names

Co-authored-by: me <me@kentcdodds.com>

Author: cursoragent

src/shared/toolNameValidation.test.ts

@@ -31,20 +31,20 @@ describe('validateToolName', () => {
       expect(result.warnings).toHaveLength(0);
     });
 
-    test('should reject names with dots', () => {
+    test('should accept names with dots', () => {
       const result = validateToolName('admin.tools.list');
-      expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name contains invalid characters: "."');
+      expect(result.isValid).toBe(true);
+      expect(result.warnings).toHaveLength(0);
     });
 
-    test('should reject names with forward slashes', () => {
+    test('should accept names with forward slashes', () => {
       const result = validateToolName('user/profile/update');
-      expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name contains invalid characters: "/"');
+      expect(result.isValid).toBe(true);
+      expect(result.warnings).toHaveLength(0);
     });
 
     test('should accept mixed character names', () => {
-      const result = validateToolName('DATA_EXPORT_v2-1');
+      const result = validateToolName('DATA_EXPORT_v2.1');
       expect(result.isValid).toBe(true);
       expect(result.warnings).toHaveLength(0);
     });
@@ -55,8 +55,8 @@ describe('validateToolName', () => {
       expect(result.warnings).toHaveLength(0);
     });
 
-    test('should accept 64 character names', () => {
-      const name = 'a'.repeat(64);
+    test('should accept 128 character names', () => {
+      const name = 'a'.repeat(128);
       const result = validateToolName(name);
       expect(result.isValid).toBe(true);
       expect(result.warnings).toHaveLength(0);
@@ -70,11 +70,11 @@ describe('validateToolName', () => {
       expect(result.warnings).toContain('Tool name cannot be empty');
     });
 
-    test('should reject names longer than 64 characters', () => {
-      const name = 'a'.repeat(65);
+    test('should reject names longer than 128 characters', () => {
+      const name = 'a'.repeat(129);
       const result = validateToolName(name);
       expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name exceeds maximum length of 64 characters (current: 65)');
+      expect(result.warnings).toContain('Tool name exceeds maximum length of 128 characters (current: 129)');
     });
 
     test('should reject names with spaces', () => {
@@ -92,7 +92,7 @@ describe('validateToolName', () => {
     test('should reject names with other special characters', () => {
       const result = validateToolName('user@domain.com');
       expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name contains invalid characters: "@", "."');
+      expect(result.warnings).toContain('Tool name contains invalid characters: "@"');
     });
 
     test('should reject names with multiple invalid characters', () => {
@@ -133,22 +133,22 @@ describe('validateToolName', () => {
       expect(result.warnings).toContain('Tool name starts or ends with a dash, which may cause parsing issues in some contexts');
     });
 
-    test('should reject names starting with dot', () => {
+    test('should warn about names starting with dot', () => {
       const result = validateToolName('.get.user');
-      expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name contains invalid characters: "."');
+      expect(result.isValid).toBe(true);
+      expect(result.warnings).toContain('Tool name starts or ends with a dot, which may cause parsing issues in some contexts');
     });
 
-    test('should reject names ending with dot', () => {
+    test('should warn about names ending with dot', () => {
       const result = validateToolName('get.user.');
-      expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name contains invalid characters: "."');
+      expect(result.isValid).toBe(true);
+      expect(result.warnings).toContain('Tool name starts or ends with a dot, which may cause parsing issues in some contexts');
     });
 
-    test('should reject names with both leading and trailing dots', () => {
+    test('should warn about names with both leading and trailing dots', () => {
       const result = validateToolName('.get.user.');
-      expect(result.isValid).toBe(false);
-      expect(result.warnings).toContain('Tool name contains invalid characters: "."');
+      expect(result.isValid).toBe(true);
+      expect(result.warnings).toContain('Tool name starts or ends with a dot, which may cause parsing issues in some contexts');
     });
   });
 });
@@ -202,18 +202,18 @@ describe('validateAndWarnToolName', () => {
   });
 
   test('should return false for names exceeding length limit', () => {
-    const longName = 'a'.repeat(65);
+    const longName = 'a'.repeat(129);
     const result = validateAndWarnToolName(longName);
     expect(result).toBe(false);
     expect(warnSpy).toHaveBeenCalled(); // Now issues warnings instead of errors
   });
 });
 
 describe('edge cases and robustness', () => {
-  test('should reject names with only dots', () => {
+  test('should warn about names with only dots', () => {
     const result = validateToolName('...');
-    expect(result.isValid).toBe(false);
-    expect(result.warnings).toContain('Tool name contains invalid characters: "."');
+    expect(result.isValid).toBe(true);
+    expect(result.warnings).toContain('Tool name starts or ends with a dot, which may cause parsing issues in some contexts');
   });
 
   test('should handle names with only dashes', () => {
@@ -222,10 +222,10 @@ describe('edge cases and robustness', () => {
     expect(result.warnings).toContain('Tool name starts or ends with a dash, which may cause parsing issues in some contexts');
   });
 
-  test('should reject names with only forward slashes', () => {
+  test('should warn about names with only forward slashes', () => {
     const result = validateToolName('///');
-    expect(result.isValid).toBe(false);
-    expect(result.warnings).toContain('Tool name contains invalid characters: "/"');
+    expect(result.isValid).toBe(true);
+    expect(result.warnings).toContain('Tool name starts or ends with a slash, which may cause parsing issues in some contexts');
   });
 
   test('should handle names with mixed valid and invalid characters', () => {

src/shared/toolNameValidation.ts

@@ -9,9 +9,9 @@
  */
 
 /**
- * Regular expression for valid tool names according to the MCP SEP specification
+ * Regular expression for valid tool names according to SEP-986 specification
  */
-const TOOL_NAME_REGEX = /^[A-Za-z0-9_-]{1,64}$/;
+const TOOL_NAME_REGEX = /^[A-Za-z0-9._/-]{1,128}$/;
 
 /**
  * Validates a tool name according to the SEP specification
@@ -32,10 +32,10 @@ export function validateToolName(name: string): {
     };
   }
 
-  if (name.length > 64) {
+  if (name.length > 128) {
     return {
       isValid: false,
-      warnings: [`Tool name exceeds maximum length of 64 characters (current: ${name.length})`]
+      warnings: [`Tool name exceeds maximum length of 128 characters (current: ${name.length})`]
     };
   }
 
@@ -48,21 +48,29 @@ export function validateToolName(name: string): {
     warnings.push("Tool name contains commas, which may cause parsing issues");
   }
 
-  // Check for potentially confusing patterns (only hyphens, not dots/slashes)
+  // Check for potentially confusing patterns (leading/trailing dashes, dots, slashes)
   if (name.startsWith('-') || name.endsWith('-')) {
     warnings.push("Tool name starts or ends with a dash, which may cause parsing issues in some contexts");
   }
 
-  // Check for invalid characters (including dots and slashes)
+  if (name.startsWith('.') || name.endsWith('.')) {
+    warnings.push("Tool name starts or ends with a dot, which may cause parsing issues in some contexts");
+  }
+  
+  if (name.startsWith('/') || name.endsWith('/')) {
+    warnings.push("Tool name starts or ends with a slash, which may cause parsing issues in some contexts");
+  }
+  
+  // Check for invalid characters
   if (!TOOL_NAME_REGEX.test(name)) {
     const invalidChars = name
       .split('')
-      .filter(char => !/[A-Za-z0-9_-]/.test(char))
+      .filter(char => !/[A-Za-z0-9._/-]/.test(char))
       .filter((char, index, arr) => arr.indexOf(char) === index); // Remove duplicates
 
     warnings.push(
       `Tool name contains invalid characters: ${invalidChars.map(c => `"${c}"`).join(', ')}`,
-      "Allowed characters are: A-Z, a-z, 0-9, underscore (_), and dash (-)"
+      "Allowed characters are: A-Z, a-z, 0-9, underscore (_), dash (-), dot (.), and forward slash (/)"
     );
 
     return {