fix(tool): bridge custom tool zod metadata (#27770)

packages/plugin/src/tool.ts

@@ -48,13 +48,7 @@ export function tool<Args extends z.ZodRawShape>(input: {
   args: Args
   execute(args: z.infer<z.ZodObject<Args>>, context: ToolContext): Promise<ToolResult>
 }) {
-  return {
-    ...input,
-    // Generate JSON Schema here with the same Zod instance that created
-    // `tool.schema` args. Zod metadata such as `.describe()` is stored in a
-    // module-local registry, so converting later from opencode can lose it.
-    jsonSchema: z.toJSONSchema(z.object(input.args), { target: "draft-7", io: "input" }),
-  }
+  return input
 }
 tool.schema = z