diff --git a/packages/server/src/ibmi-mcp-server/utils/config/toolConfigBuilder.ts b/packages/server/src/ibmi-mcp-server/utils/config/toolConfigBuilder.ts
index 121544d..16ca71a 100644
--- a/packages/server/src/ibmi-mcp-server/utils/config/toolConfigBuilder.ts
+++ b/packages/server/src/ibmi-mcp-server/utils/config/toolConfigBuilder.ts
@@ -7,7 +7,7 @@
  */
 
 import { z } from "zod";
-import { resolve, join } from "path";
+import { resolve } from "path";
 import { existsSync } from "fs";
 import { glob } from "glob";
 import {
@@ -727,8 +727,11 @@ export class ToolConfigBuilder {
       );
     }
 
-    const pattern = join(resolvedDir, "**/*.{yaml,yml}");
-    return glob.sync(pattern, { absolute: true });
+    // glob requires forward-slash patterns even on Windows; backslashes are
+    // interpreted as escape characters, not path separators. Pass the resolved
+    // directory via `cwd` (a filesystem path, so separators are fine there) and
+    // keep the pattern forward-slash only so directory sources work on Windows.
+    return glob.sync("**/*.{yaml,yml}", { cwd: resolvedDir, absolute: true });
   }
 
   /**
@@ -736,13 +739,15 @@ export class ToolConfigBuilder {
    * @private
    */
   private resolveGlobPaths(pattern: string, baseDir?: string): string[] {
-    const searchPattern = baseDir ? join(baseDir, pattern) : pattern;
-    const paths = glob.sync(searchPattern, { absolute: true });
+    // Resolve the pattern relative to baseDir via glob's `cwd` option rather
+    // than join(), which would corrupt the forward-slash glob pattern into
+    // backslashes on Windows (glob treats backslashes as escape characters).
+    const paths = glob.sync(pattern, { absolute: true, cwd: baseDir });
 
     if (paths.length === 0) {
       throw new McpError(
         JsonRpcErrorCode.ConfigurationError,
-        `No files found matching pattern: ${searchPattern}`,
+        `No files found matching pattern: ${baseDir ? `${baseDir} :: ${pattern}` : pattern}`,
       );
     }
 
diff --git a/packages/server/tests/ibmi-mcp-server/utils/config/toolConfigBuilder.pathResolution.test.ts b/packages/server/tests/ibmi-mcp-server/utils/config/toolConfigBuilder.pathResolution.test.ts
new file mode 100644
index 0000000..e2d06f3
--- /dev/null
+++ b/packages/server/tests/ibmi-mcp-server/utils/config/toolConfigBuilder.pathResolution.test.ts
@@ -0,0 +1,87 @@
+/**
+ * @fileoverview Path-resolution tests for ToolConfigBuilder.
+ *
+ * Covers the directory and glob source resolution used when `--tools` points at
+ * a directory (or a glob) rather than a single YAML file.
+ *
+ * Regression guard for the Windows bug where a glob pattern was built with
+ * path.join(), producing backslashes that glob (v10+) treats as escape
+ * characters rather than path separators, so no tool files were discovered.
+ * The fix passes the directory via glob's `cwd` option and keeps the pattern
+ * forward-slash only. See IBM/ibmi-mcp-server#150.
+ */
+
+import { describe, it, expect, beforeAll, afterAll, vi } from "vitest";
+import { mkdtempSync, mkdirSync, writeFileSync, rmSync } from "fs";
+import { tmpdir } from "os";
+import { join, resolve } from "path";
+
+// Block the scheduler singleton (loaded transitively via the utils barrel).
+vi.mock("../../../../src/utils/scheduling/index.js", () => ({
+  SchedulerService: { getInstance: vi.fn() },
+  schedulerService: {},
+}));
+
+import { ToolConfigBuilder } from "../../../../src/ibmi-mcp-server/utils/config/toolConfigBuilder.js";
+
+// resolveDirectoryPaths / resolveGlobPaths are private; exercise them directly
+// via the singleton instance to keep the test focused on path resolution
+// without standing up the full YAML-parsing pipeline.
+type PathResolver = {
+  resolveDirectoryPaths(directoryPath: string): string[];
+  resolveGlobPaths(pattern: string, baseDir?: string): string[];
+};
+
+describe("ToolConfigBuilder path resolution", () => {
+  let tmpRoot: string;
+  let builder: PathResolver;
+
+  beforeAll(() => {
+    builder = ToolConfigBuilder.getInstance() as unknown as PathResolver;
+
+    tmpRoot = mkdtempSync(join(tmpdir(), "ibmi-tools-"));
+    mkdirSync(join(tmpRoot, "nested"), { recursive: true });
+
+    writeFileSync(join(tmpRoot, "a.yaml"), "tools: {}\n");
+    writeFileSync(join(tmpRoot, "b.yml"), "tools: {}\n");
+    writeFileSync(join(tmpRoot, "nested", "c.yaml"), "tools: {}\n");
+    // Non-YAML files must be ignored.
+    writeFileSync(join(tmpRoot, "README.md"), "ignore me\n");
+  });
+
+  afterAll(() => {
+    rmSync(tmpRoot, { recursive: true, force: true });
+  });
+
+  it("finds all .yaml and .yml files in a directory (including nested)", () => {
+    const paths = builder.resolveDirectoryPaths(tmpRoot);
+
+    expect(paths).toHaveLength(3);
+    // Returned paths are absolute and forward-slash-comparable.
+    const names = paths.map((p) => p.split(/[\\/]/).pop()).sort();
+    expect(names).toEqual(["a.yaml", "b.yml", "c.yaml"]);
+    for (const p of paths) {
+      expect(resolve(p)).toBe(p);
+    }
+  });
+
+  it("throws a configuration error for a missing directory", () => {
+    expect(() =>
+      builder.resolveDirectoryPaths(join(tmpRoot, "does-not-exist")),
+    ).toThrow(/Configuration directory not found/);
+  });
+
+  it("resolves a relative glob pattern against baseDir", () => {
+    const paths = builder.resolveGlobPaths("**/*.{yaml,yml}", tmpRoot);
+
+    expect(paths).toHaveLength(3);
+    const names = paths.map((p) => p.split(/[\\/]/).pop()).sort();
+    expect(names).toEqual(["a.yaml", "b.yml", "c.yaml"]);
+  });
+
+  it("throws when a glob pattern matches nothing", () => {
+    expect(() => builder.resolveGlobPaths("**/*.json", tmpRoot)).toThrow(
+      /No files found matching pattern/,
+    );
+  });
+});