diff --git a/open-sse/translator/request/claude-to-openai.ts b/open-sse/translator/request/claude-to-openai.ts
index dda41d3aef..cb682b16a7 100644
--- a/open-sse/translator/request/claude-to-openai.ts
+++ b/open-sse/translator/request/claude-to-openai.ts
@@ -39,7 +39,10 @@ function isClaudeServerWebSearchTool(tool: unknown): tool is JsonRecord {
 
 function toStringArray(value: unknown): string[] {
   if (!Array.isArray(value)) return [];
-  return value.map((entry) => String(entry || "").trim()).filter(Boolean);
+  return value
+    .filter((entry): entry is string => typeof entry === "string")
+    .map((entry) => entry.trim())
+    .filter(Boolean);
 }
 
 function convertClaudeServerWebSearchTool(tool: JsonRecord): JsonRecord {
@@ -132,15 +135,17 @@ export function claudeToOpenAIRequest(model, body, stream) {
           return convertClaudeServerWebSearchTool(tool);
         }
 
-        const name = typeof tool.name === "string" ? tool.name.trim() : "";
+        if (!tool || typeof tool !== "object" || Array.isArray(tool)) return null;
+        const record = tool as JsonRecord;
+        const name = typeof record.name === "string" ? record.name.trim() : "";
         if (!name) return null; // skip tools with empty/invalid name
 
         return {
           type: "function",
           function: {
             name,
-            description: typeof tool.description === "string" ? tool.description : "", // fix: never null (#276)
-            parameters: normalizeToolSchema(tool.input_schema),
+            description: typeof record.description === "string" ? record.description : "", // fix: never null (#276)
+            parameters: normalizeToolSchema(record.input_schema),
           },
         };
       })
diff --git a/tests/unit/translator-claude-to-openai.test.ts b/tests/unit/translator-claude-to-openai.test.ts
index 5a9e084186..c14bdfccc3 100644
--- a/tests/unit/translator-claude-to-openai.test.ts
+++ b/tests/unit/translator-claude-to-openai.test.ts
@@ -63,8 +63,8 @@ test("Claude -> OpenAI maps Claude server WebSearch to native Responses web_sear
         {
           type: "web_search_20250305",
           name: "web_search",
-          allowed_domains: ["docs.anthropic.com", ""],
-          blocked_domains: ["spam.example"],
+          allowed_domains: ["docs.anthropic.com", "", 123, { domain: "bad.example" }],
+          blocked_domains: ["spam.example", false],
           max_uses: 8,
           user_location: { type: "approximate", country: "US" },
         },
@@ -87,6 +87,28 @@ test("Claude -> OpenAI maps Claude server WebSearch to native Responses web_sear
   assert.deepEqual(result.tool_choice, { type: "web_search" });
 });
 
+test("Claude -> OpenAI skips invalid tool payloads without crashing", () => {
+  const result = claudeToOpenAIRequest(
+    "gpt-4o",
+    {
+      messages: [{ role: "user", content: "hi" }],
+      tools: [null, "bad", 42, [], { name: "", input_schema: { type: "object" } }, { name: "ok" }],
+    },
+    false
+  );
+
+  assert.deepEqual(result.tools, [
+    {
+      type: "function",
+      function: {
+        name: "ok",
+        description: "",
+        parameters: { type: "object", properties: {} },
+      },
+    },
+  ]);
+});
+
 test("Claude -> OpenAI leaves ordinary web_search function tools as functions", () => {
   const result = claudeToOpenAIRequest(
     "gpt-4o",