fix: allow media-only sends

src/infra/outbound/message-action-runner.test.ts

@@ -37,6 +37,37 @@ describe("runMessageAction context isolation", () => {
     expect(result.kind).toBe("send");
   });
 
+  it("allows media-only send when target matches current channel", async () => {
+    const result = await runMessageAction({
+      cfg: slackConfig,
+      action: "send",
+      params: {
+        channel: "slack",
+        to: "#C123",
+        media: "https://example.com/note.ogg",
+      },
+      toolContext: { currentChannelId: "C123" },
+      dryRun: true,
+    });
+
+    expect(result.kind).toBe("send");
+  });
+
+  it("requires message when no media hint is provided", async () => {
+    await expect(
+      runMessageAction({
+        cfg: slackConfig,
+        action: "send",
+        params: {
+          channel: "slack",
+          to: "#C123",
+        },
+        toolContext: { currentChannelId: "C123" },
+        dryRun: true,
+      }),
+    ).rejects.toThrow(/message required/i);
+  });
+
   it("blocks send when target differs from current channel", async () => {
     await expect(
       runMessageAction({

src/infra/outbound/message-action-runner.ts

@@ -208,10 +208,12 @@ export async function runMessageAction(
 
   if (action === "send") {
     const to = readStringParam(params, "to", { required: true });
+    // Allow message to be omitted when sending media-only (e.g., voice notes)
+    const mediaHint = readStringParam(params, "media", { trim: false });
     let message = readStringParam(params, "message", {
-      required: true,
+      required: !mediaHint, // Only require message if no media hint
       allowEmpty: true,
-    });
+    }) ?? "";
 
     const parsed = parseReplyDirectives(message);
     message = parsed.text;