diff --git a/langchain-core/src/runnables/tool.ts b/langchain-core/src/runnables/tool.ts
index b1a990019f7f..eec6be2a61a6 100644
--- a/langchain-core/src/runnables/tool.ts
+++ b/langchain-core/src/runnables/tool.ts
@@ -1 +1,34 @@
-// todo implement
\ No newline at end of file
+import { ZodAny } from "../types/zod.js";
+import { RunnableLambda } from "./base.js";
+import { RunnableConfig } from "./config.js";
+
+export interface RunnableToolLikeFields<RunInput, RunOutput> {
+  name?: string;
+
+  description?: string;
+
+  schema: RunInput;
+
+  func:
+    | ((input: RunInput, config?: RunnableConfig) => RunOutput)
+    | ((input: RunInput, config?: RunnableConfig) => Promise<RunOutput>);
+}
+
+export class RunnableToolLike<
+  RunInput extends ZodAny,
+  RunOutput = string
+> extends RunnableLambda<RunInput, RunOutput> {
+  description?: string;
+
+  schema: RunInput;
+
+  constructor(fields: RunnableToolLikeFields<RunInput, RunOutput>) {
+    super({
+      func: fields.func,
+    });
+
+    this.name = fields.name;
+    this.description = fields.description;
+    this.schema = fields.schema;
+  }
+}
diff --git a/langchain-core/src/tools.ts b/langchain-core/src/tools.ts
index 252571ca084a..5adc4d27b4e4 100644
--- a/langchain-core/src/tools.ts
+++ b/langchain-core/src/tools.ts
@@ -11,9 +11,7 @@ import {
 } from "./language_models/base.js";
 import { ensureConfig, type RunnableConfig } from "./runnables/config.js";
 import type { RunnableFunc, RunnableInterface } from "./runnables/base.js";
-
-// eslint-disable-next-line @typescript-eslint/no-explicit-any
-type ZodAny = z.ZodObject<any, any, any, any>;
+import { ZodAny } from "./types/zod.js";
 
 /**
  * Parameters for the Tool classes.
diff --git a/langchain-core/src/types/zod.ts b/langchain-core/src/types/zod.ts
new file mode 100644
index 000000000000..d864170ddafa
--- /dev/null
+++ b/langchain-core/src/types/zod.ts
@@ -0,0 +1,4 @@
+import type { z } from "zod";
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type ZodAny = z.ZodObject<any, any, any, any>;