diff --git a/packages/core/src/tool-output.ts b/packages/core/src/tool-output.ts
index 4e28cbbbec7..cc30f5976b6 100644
--- a/packages/core/src/tool-output.ts
+++ b/packages/core/src/tool-output.ts
@@ -6,8 +6,8 @@ import { Context, Duration, Effect, Layer, Schedule } from "effect"
 import { makeGlobalNode, makeLocationNode } from "@opencode/util/effect/app-node"
 import { FSUtil } from "@opencode/util/fs-util"
 import { Global } from "@opencode/util/global"
+import { Identifier } from "@opencode/schema/identifier"
 import { FileRetention } from "./file-retention.js"
-import { Identifier } from "./id/id.js"
 import { State } from "./state.js"
 
 export const MAX_LINES = 2_000
@@ -15,6 +15,8 @@ export const MAX_BYTES = 50 * 1024 // 50 KiB
 export const RETENTION = Duration.days(7)
 export const DIRECTORY = "tool-output"
 
+export const fileName = (timestamp?: number) => "tool_" + Identifier.create(false, timestamp)
+
 type Result = Tool.NormalizedResult
 
 type Limits = {
@@ -81,7 +83,7 @@ const layer = Layer.effect(
         kept.push(line)
         bytes += size
       }
-      const file = path.join(directory, Identifier.ascending("tool"))
+      const file = path.join(directory, fileName())
       yield* fs.ensureDir(directory).pipe(Effect.orDie)
       yield* fs.writeFileString(file, text).pipe(Effect.orDie)
       const shown = kept.length > 0 ? `lines 1-${kept.length}` : "0 lines"
diff --git a/packages/core/test/tool-output.test.ts b/packages/core/test/tool-output.test.ts
index 1bb8b578b30..535611c618e 100644
--- a/packages/core/test/tool-output.test.ts
+++ b/packages/core/test/tool-output.test.ts
@@ -7,7 +7,6 @@ import { ToolOutput } from "@opencode/core/tool-output"
 import type { Tool } from "@opencode/core/tool"
 import { FSUtil } from "@opencode/util/fs-util"
 import { Global } from "@opencode/util/global"
-import { Identifier } from "@opencode/core/id/id"
 import { tmpdir } from "./fixture/tmpdir"
 import { it } from "./lib/effect"
 
@@ -141,8 +140,8 @@ describe("ToolOutput", () => {
     withStore((output, fs, root) =>
       Effect.gen(function* () {
         const directory = path.join(root, ToolOutput.DIRECTORY)
-        const old = path.join(directory, Identifier.create("tool", "ascending", 2 ** 36 - 1))
-        const recent = path.join(directory, Identifier.create("tool", "ascending", 2 ** 36 + 1))
+        const old = path.join(directory, ToolOutput.fileName(2 ** 36 - 1))
+        const recent = path.join(directory, ToolOutput.fileName(2 ** 36 + 1))
         yield* fs.ensureDir(directory)
         yield* fs.writeFileString(old, "old")
         yield* fs.writeFileString(recent, "recent")