diff --git a/src/hooks/question-label-truncator/hook.ts b/src/hooks/question-label-truncator/hook.ts
index a43fa4fc7..ed28a394a 100644
--- a/src/hooks/question-label-truncator/hook.ts
+++ b/src/hooks/question-label-truncator/hook.ts
@@ -1,3 +1,5 @@
+import { replaceToolArgs } from "../../shared/replace-tool-args"
+
 const MAX_LABEL_LENGTH = 30;
 
 interface QuestionOption {
@@ -56,7 +58,7 @@ export function createQuestionLabelTruncatorHook() {
       if (toolName === "askuserquestion" || toolName === "ask_user_question") {
         if (hasQuestions(output.args)) {
           const truncatedArgs = truncateQuestionLabels(output.args);
-          Object.assign(output.args, truncatedArgs);
+          replaceToolArgs(output, { questions: truncatedArgs.questions });
         }
       }
     },
diff --git a/src/hooks/webfetch-redirect-guard/hook.ts b/src/hooks/webfetch-redirect-guard/hook.ts
index 1599bc1eb..055498fe6 100644
--- a/src/hooks/webfetch-redirect-guard/hook.ts
+++ b/src/hooks/webfetch-redirect-guard/hook.ts
@@ -1,5 +1,5 @@
 import type { PluginInput } from "@opencode-ai/plugin"
-import { log } from "../../shared"
+import { log, replaceToolArgs } from "../../shared"
 import {
   MAX_WEBFETCH_REDIRECTS,
   WEBFETCH_REDIRECT_ERROR_PATTERNS,
@@ -85,7 +85,7 @@ export function createWebFetchRedirectGuardHook(_ctx: PluginInput) {
         })
 
         if (resolution.type === "resolved") {
-          output.args.url = resolution.url
+          replaceToolArgs(output, { url: resolution.url })
           return
         }
 
diff --git a/src/plugin/tool-execute-before.ts b/src/plugin/tool-execute-before.ts
index 3b66aa2c9..ce1129ccc 100644
--- a/src/plugin/tool-execute-before.ts
+++ b/src/plugin/tool-execute-before.ts
@@ -3,7 +3,7 @@ import { randomUUID } from "node:crypto"
 
 import { getMainSessionID } from "../features/claude-code-session-state"
 import { clearBoulderState } from "../features/boulder-state"
-import { log } from "../shared"
+import { log, replaceToolArgs } from "../shared"
 import { stripInvisibleAgentCharacters } from "../shared/agent-display-names"
 import { resolveSessionAgent } from "./session-agent-resolver"
 import { parseRalphLoopArguments } from "../hooks/ralph-loop/command-arguments"
@@ -54,7 +54,7 @@ export function createToolExecuteBeforeHandler(args: {
   return async (input, output): Promise<void> => {
     if (input.tool.toLowerCase() === "bash" && typeof output.args.command === "string") {
       if (output.args.command.includes("\x00")) {
-        output.args.command = output.args.command.replace(/\x00/g, "")
+        replaceToolArgs(output, { command: output.args.command.replace(/\x00/g, "") })
         log("[tool-execute-before] Stripped null bytes from bash command", {
           sessionID: input.sessionID,
           callID: input.callID,