diff --git a/packages/agent/src/adapters/local-tools/tools/signed-commit.test.ts b/packages/agent/src/adapters/local-tools/tools/signed-commit.test.ts
index 33378c3f1f..5502dacd3b 100644
--- a/packages/agent/src/adapters/local-tools/tools/signed-commit.test.ts
+++ b/packages/agent/src/adapters/local-tools/tools/signed-commit.test.ts
@@ -117,6 +117,41 @@ describe("signed-commit tool handler", () => {
     });
   });
 
+  it("persists the branch when cwd uses an equivalent path representation", async () => {
+    await signedCommitTool.handler(
+      {
+        cwd: "/tmp/workspace/repos/posthog/code/.",
+        token: "ghs_x",
+        taskId: "task-1",
+        taskRunId: "run-1",
+      },
+      { message: "chore: bump", cwd: "." },
+    );
+
+    expect(reportTaskRunBranch).toHaveBeenCalledWith({
+      taskId: "task-1",
+      taskRunId: "run-1",
+      branch: "posthog-code/feature",
+    });
+  });
+
+  it("does not persist a branch created in a sibling repository", async () => {
+    await signedCommitTool.handler(
+      {
+        cwd: "/tmp/workspace/repos/posthog/code",
+        token: "ghs_x",
+        taskId: "task-1",
+        taskRunId: "run-1",
+      },
+      {
+        message: "chore: bump",
+        cwd: "/tmp/workspace/repos/posthog/grafana-dashboards",
+      },
+    );
+
+    expect(reportTaskRunBranch).not.toHaveBeenCalled();
+  });
+
   it("returns the no-token error without invoking createSignedCommit", async () => {
     const savedGh = process.env.GH_TOKEN;
     const savedGithub = process.env.GITHUB_TOKEN;
diff --git a/packages/agent/src/adapters/local-tools/tools/signed-git-tool.ts b/packages/agent/src/adapters/local-tools/tools/signed-git-tool.ts
index 0b72c25875..cdeae219d0 100644
--- a/packages/agent/src/adapters/local-tools/tools/signed-git-tool.ts
+++ b/packages/agent/src/adapters/local-tools/tools/signed-git-tool.ts
@@ -43,10 +43,14 @@ export function defineSignedGitTool<S extends z.ZodRawShape, R>(opts: {
         string,
         unknown
       >;
-      const cwd = argCwd ? path.resolve(ctx.cwd, argCwd) : ctx.cwd;
+      const taskRepositoryCwd = path.resolve(ctx.cwd);
+      const cwd = argCwd
+        ? path.resolve(taskRepositoryCwd, argCwd)
+        : taskRepositoryCwd;
       return opts.run(
         {
           cwd,
+          taskRepositoryCwd,
           token,
           taskId: ctx.taskId,
           taskRunId: ctx.taskRunId,
diff --git a/packages/agent/src/adapters/signed-commit-shared.ts b/packages/agent/src/adapters/signed-commit-shared.ts
index aa7e8523b4..2cdd83eb7d 100644
--- a/packages/agent/src/adapters/signed-commit-shared.ts
+++ b/packages/agent/src/adapters/signed-commit-shared.ts
@@ -135,7 +135,11 @@ export interface SignedCommitToolResult {
   [key: string]: unknown;
 }
 
-export type SignedCommitToolCtx = SignedCommitCtx & { taskRunId?: string };
+export type SignedCommitToolCtx = SignedCommitCtx & {
+  taskRunId?: string;
+  /** The task repository cwd, before a tool-call `cwd` override is applied. */
+  taskRepositoryCwd: string;
+};
 
 async function runSignedTool<A>(
   toolName: string,
@@ -176,11 +180,17 @@ export function runSignedCommitTool(
     SIGNED_COMMIT_TOOL_NAME,
     async (c, a: SignedCommitInput) => {
       const result = await createSignedCommit(c, a);
-      await reportTaskRunBranch({
-        taskId: ctx.taskId,
-        taskRunId: ctx.taskRunId,
-        branch: result.branch,
-      });
+      // TaskRun.branch is the branch that provisioning checks out in the task's
+      // repository on resume. A task can also commit to sibling repositories by
+      // passing `cwd`; persisting one of those branches here makes the next run
+      // try to clone the task repository at a branch that only exists elsewhere.
+      if (ctx.cwd === ctx.taskRepositoryCwd) {
+        await reportTaskRunBranch({
+          taskId: ctx.taskId,
+          taskRunId: ctx.taskRunId,
+          branch: result.branch,
+        });
+      }
       // The "commit hook": every pushed commit becomes a `commit` artefact on the signal
       // reports this task is associated with. Best-effort and awaited inside the tool's
       // try/catch-free success path — reportCommitArtefacts never throws, so a failed