adjust edit tool multiple matches error wording (#3418)

packages/opencode/src/tool/edit.ts

@@ -621,6 +621,6 @@ export function replace(content: string, oldString: string, newString: string, r
     throw new Error("oldString not found in content")
   }
   throw new Error(
-    "oldString found multiple times and requires more code context to uniquely identify the intended match",
+    "Found multiple matches for oldString. Include more surrounding code lines in oldString to uniquely identify which occurrence to replace.",
   )
 }