diff --git a/packages/core/src/agents/toml-loader.test.ts b/packages/core/src/agents/toml-loader.test.ts
index 68f130a611c..17c9b962fc5 100644
--- a/packages/core/src/agents/toml-loader.test.ts
+++ b/packages/core/src/agents/toml-loader.test.ts
@@ -107,7 +107,7 @@ describe('toml-loader', () => {
       const filePath = await writeAgentToml(`
         name = "test-agent"
         description = "A test agent"
-        tools = ["not-a-tool"]
+        tools = ["tool!"]
         [prompts]
         system_prompt = "You are a test agent."
       `);
diff --git a/packages/core/src/tools/tool-names.test.ts b/packages/core/src/tools/tool-names.test.ts
index 805727c283e..c3335f9021d 100644
--- a/packages/core/src/tools/tool-names.test.ts
+++ b/packages/core/src/tools/tool-names.test.ts
@@ -30,9 +30,14 @@ describe('tool-names', () => {
       expect(isValidToolName('my-server__my-tool')).toBe(true);
     });
 
+    it('should validate generic slug names (unprefixed tools)', () => {
+      expect(isValidToolName('search_for_files_codesearch')).toBe(true);
+      expect(isValidToolName('simple-tool-name')).toBe(true);
+      expect(isValidToolName('tool_with_underscores')).toBe(true);
+    });
+
     it('should reject invalid tool names', () => {
       expect(isValidToolName('')).toBe(false);
-      expect(isValidToolName('invalid-name')).toBe(false);
       expect(isValidToolName('server__')).toBe(false);
       expect(isValidToolName('__tool')).toBe(false);
       expect(isValidToolName('server__tool__extra')).toBe(false);
diff --git a/packages/core/src/tools/tool-names.ts b/packages/core/src/tools/tool-names.ts
index db2967405e2..83ee9538dde 100644
--- a/packages/core/src/tools/tool-names.ts
+++ b/packages/core/src/tools/tool-names.ts
@@ -88,5 +88,7 @@ export function isValidToolName(
     return slugRegex.test(server) && slugRegex.test(tool);
   }
 
-  return false;
+  // Allow any valid slug to support unprefixed MCP tools or other dynamic tools
+  const slugRegex = /^[a-z0-9-_]+$/i;
+  return slugRegex.test(name);
 }