diff --git a/packages/core/src/plugin/tool-input-repair.ts b/packages/core/src/plugin/tool-input-repair.ts
index 984f7f343f1b..c2e1f03b3628 100644
--- a/packages/core/src/plugin/tool-input-repair.ts
+++ b/packages/core/src/plugin/tool-input-repair.ts
@@ -1,8 +1,9 @@
 export * as ToolInputRepairPlugin from "./tool-input-repair.js"
 
+import { ToolFailure } from "@opencode/ai/effect"
 import { define } from "@opencode/plugin/effect/plugin"
 import { Effect, JsonSchema, Option, Predicate, Schema } from "effect"
-import { definition } from "../tool/runtime.js"
+import { definition, normalizeContent } from "../tool/runtime.js"
 
 // Repairs apply only when the input schema unambiguously supports them:
 // - Stringified root or nested object: '{"limit":"20"}' -> { limit: 20 }
@@ -18,21 +19,56 @@ import { definition } from "../tool/runtime.js"
 const decodeJson = Schema.decodeUnknownOption(Schema.fromJsonString(Schema.Unknown))
 const maxDepth = 6
 
+// Tool names models carry over from other harnesses, used only when no tool has that name.
+// The result tells the model which tool ran, so it calls that one next time.
+const aliases = new Map([["bash", "shell"]])
+
 export const Plugin = define({
   id: "opencode.tool.input.repair",
   effect: (ctx) =>
-    ctx.tool.hook("execute.before", (event) =>
-      Effect.gen(function* () {
-        // The outer Code Mode tool is built per snapshot rather than registered, so it cannot be
-        // looked up here. Its `{ code }` input is trivial; the tools it calls are repaired normally.
-        if (event.tool === "execute") return
-        const tool = (yield* ctx.tool.list()).find((tool) => tool.id === event.tool)
-        if (!tool) return
-        const schema = definition(tool).inputSchema
-        if (schema.type !== "object") return
-        event.input = repair(event.input, schema, schema, 0)
-      }),
-    ),
+    Effect.gen(function* () {
+      const aliased = new Map<string, string>()
+      yield* ctx.tool.hook("execute.before", (event) =>
+        Effect.gen(function* () {
+          // The outer Code Mode tool is built per snapshot rather than registered, so it cannot be
+          // looked up here. Its `{ code }` input is trivial; the tools it calls are repaired normally.
+          if (event.tool === "execute") return
+          const tools = yield* ctx.tool.list()
+          const alias = aliases.get(event.tool)
+          const tool =
+            tools.find((tool) => tool.id === event.tool) ??
+            (alias === undefined ? undefined : tools.find((tool) => tool.id === alias))
+          if (!tool) return
+          if (tool.id !== event.tool) {
+            aliased.set(event.id, event.tool)
+            event.tool = tool.id
+          }
+          const schema = definition(tool).inputSchema
+          if (schema.type !== "object") return
+          event.input = repair(event.input, schema, schema, 0)
+        }),
+      )
+      yield* ctx.tool.hook("execute.after", (event) =>
+        Effect.sync(() => {
+          const called = aliased.get(event.id)
+          if (called === undefined) return
+          aliased.delete(event.id)
+          const note = `There is no "${called}" tool, so this ran as "${event.tool}". Call "${event.tool}" directly.`
+          if (event.status === "error") {
+            event.error = new ToolFailure({
+              message: `${event.error.message}\n\n${note}`,
+              error: event.error.error,
+              metadata: event.error.metadata,
+            })
+            return
+          }
+          event.result = {
+            ...event.result,
+            content: [...normalizeContent(event.result.content, event.result.output), { type: "text", text: note }],
+          }
+        }),
+      )
+    }),
 })
 
 function repair(value: unknown, schema: JsonSchema.JsonSchema, root: JsonSchema.JsonSchema, depth: number): unknown {
diff --git a/packages/core/test/plugin/tool-input-repair-integration.test.ts b/packages/core/test/plugin/tool-input-repair-integration.test.ts
index 3e3f9828cc3b..38578f105c81 100644
--- a/packages/core/test/plugin/tool-input-repair-integration.test.ts
+++ b/packages/core/test/plugin/tool-input-repair-integration.test.ts
@@ -83,6 +83,47 @@ it.effect("repairs tool input before validating its original schema", () =>
   }),
 )
 
+it.effect("runs a call to another harness's tool name as the matching tool and says so", () =>
+  Effect.gen(function* () {
+    const plugins = yield* Plugin.Service
+    const registry = yield* Tool.Service
+    const executed: unknown[] = []
+    yield* plugins.activate([
+      { ...ToolInputRepairPlugin.Plugin, revision: "1" },
+      {
+        id: "shell-tool",
+        revision: "1",
+        effect: (ctx) =>
+          ctx.tool.transform((draft) =>
+            draft.add({
+              name: "shell",
+              options: { codemode: false },
+              description: "Shell",
+              input: Schema.Struct({ command: Schema.String, timeout: Schema.optionalKey(Schema.Int) }),
+              execute: (input) => Effect.sync(() => executed.push(input)).pipe(Effect.as({ content: "done" })),
+            }),
+          ),
+      },
+    ])
+    const snapshot = yield* registry.snapshot()
+    const result = yield* snapshot.execute({
+      ...identity,
+      call: { type: "tool-call", id: "call-bash", name: "bash", input: { command: "ls", timeout: "5000" } },
+    })
+    expect(executed).toEqual([{ command: "ls", timeout: 5000 }])
+    expect(result.content).toEqual([
+      { type: "text", text: "done" },
+      { type: "text", text: 'There is no "bash" tool, so this ran as "shell". Call "shell" directly.' },
+    ])
+
+    const direct = yield* snapshot.execute({
+      ...identity,
+      call: { type: "tool-call", id: "call-shell", name: "shell", input: { command: "pwd" } },
+    })
+    expect(direct.content).toEqual([{ type: "text", text: "done" }])
+  }),
+)
+
 it.effect("repairs namespaced inner tool input called from Code Mode", () =>
   Effect.gen(function* () {
     const plugins = yield* Plugin.Service