diff --git a/__tests__/run-command.test.js b/__tests__/run-command.test.js
new file mode 100644
index 000000000..014a7db50
--- /dev/null
+++ b/__tests__/run-command.test.js
@@ -0,0 +1,81 @@
+"use strict";
+
+/**
+ * Coverage for cli/run.js — the `supercli run <plugin> <resource> <action>`
+ * one-shot discover+install+execute command (issue #335).
+ *
+ * These tests cover the usage-validation paths, which return before any
+ * network/catalog/install calls. cli/executor is mocked with an explicit
+ * factory (rather than left to load for real) since it pulls in the vm2
+ * native sandbox, which these tests have no need to exercise.
+ */
+
+jest.mock("../cli/executor", () => ({ execute: jest.fn() }));
+
+const { handleRunCommand } = require("../cli/run");
+
+describe("handleRunCommand — usage validation", () => {
+  test("missing plugin name reports invalid_argument with usage message", async () => {
+    const outputError = jest.fn();
+    const output = jest.fn();
+
+    await handleRunCommand({
+      positional: ["run"],
+      flags: {},
+      humanMode: false,
+      output,
+      outputError,
+    });
+
+    expect(output).not.toHaveBeenCalled();
+    expect(outputError).toHaveBeenCalledWith(
+      expect.objectContaining({
+        code: 85,
+        type: "invalid_argument",
+        message: expect.stringContaining("Usage: supercli run"),
+        recoverable: false,
+      })
+    );
+  });
+
+  test("missing resource/action reports invalid_argument scoped to the plugin", async () => {
+    const outputError = jest.fn();
+    const output = jest.fn();
+
+    await handleRunCommand({
+      positional: ["run", "claude-session-optimizer"],
+      flags: {},
+      humanMode: false,
+      output,
+      outputError,
+    });
+
+    expect(output).not.toHaveBeenCalled();
+    expect(outputError).toHaveBeenCalledWith(
+      expect.objectContaining({
+        code: 85,
+        type: "invalid_argument",
+        message: "Usage: supercli run claude-session-optimizer <resource> <action> [--args]",
+        recoverable: false,
+      })
+    );
+  });
+
+  test("missing action alone also reports invalid_argument", async () => {
+    const outputError = jest.fn();
+    const output = jest.fn();
+
+    await handleRunCommand({
+      positional: ["run", "claude-session-optimizer", "self"],
+      flags: {},
+      humanMode: false,
+      output,
+      outputError,
+    });
+
+    expect(output).not.toHaveBeenCalled();
+    expect(outputError).toHaveBeenCalledWith(
+      expect.objectContaining({ code: 85, type: "invalid_argument" })
+    );
+  });
+});
diff --git a/__tests__/skills-mcp.test.js b/__tests__/skills-mcp.test.js
new file mode 100644
index 000000000..ed1fcd005
--- /dev/null
+++ b/__tests__/skills-mcp.test.js
@@ -0,0 +1,58 @@
+"use strict";
+
+const { buildMcpServersUsageSkillMarkdown } = require("../cli/skills-mcp");
+
+function fakeRenderYamlObject(obj) {
+  return JSON.stringify(obj);
+}
+
+describe("buildMcpServersUsageSkillMarkdown", () => {
+  test("wraps rendered frontmatter in --- fences followed by the instruction body", () => {
+    const md = buildMcpServersUsageSkillMarkdown({ renderYamlObject: fakeRenderYamlObject });
+
+    expect(md.startsWith("---\n")).toBe(true);
+    expect(md).toContain("\n---\n\n# Instruction");
+    expect(md).toContain("supercli mcp list --json");
+  });
+
+  test("omits the dag field by default", () => {
+    let capturedFrontmatter;
+    buildMcpServersUsageSkillMarkdown({
+      renderYamlObject: (obj) => {
+        capturedFrontmatter = obj;
+        return "";
+      },
+    });
+
+    expect(capturedFrontmatter.dag).toBeUndefined();
+    expect(capturedFrontmatter.command).toBe("skills get mcp.servers.usage");
+  });
+
+  test("includes the reasoning DAG when showDag is true", () => {
+    let capturedFrontmatter;
+    buildMcpServersUsageSkillMarkdown({
+      showDag: true,
+      renderYamlObject: (obj) => {
+        capturedFrontmatter = obj;
+        return "";
+      },
+    });
+
+    expect(Array.isArray(capturedFrontmatter.dag)).toBe(true);
+    expect(capturedFrontmatter.dag).toHaveLength(4);
+    expect(capturedFrontmatter.dag[0]).toMatchObject({ id: 1, type: "list_or_register_mcp_server" });
+  });
+
+  test("honors a custom skillId in both the command and dag-less frontmatter", () => {
+    let capturedFrontmatter;
+    buildMcpServersUsageSkillMarkdown({
+      skillId: "mcp.custom.usage",
+      renderYamlObject: (obj) => {
+        capturedFrontmatter = obj;
+        return "";
+      },
+    });
+
+    expect(capturedFrontmatter.command).toBe("skills get mcp.custom.usage");
+  });
+});