diff --git a/open-sse/translator/concerns/kiroConversation.js b/open-sse/translator/concerns/kiroConversation.js
index 5ac1485b..b19e9ba6 100644
--- a/open-sse/translator/concerns/kiroConversation.js
+++ b/open-sse/translator/concerns/kiroConversation.js
@@ -48,7 +48,6 @@ function uniqueName(rawName, index, usedNames) {
   const cleaned = String(rawName || "")
     .trim()
     .replace(TOOL_NAME_PATTERN, "_")
-    .replace(/_+/g, "_")
     .replace(/^_+|_+$/g, "");
   const base = trimCodePoints(cleaned || `tool_${index + 1}`, KIRO_TOOL_NAME_MAX_LENGTH);
   let candidate = base;
diff --git a/open-sse/translator/response/kiro-to-claude.js b/open-sse/translator/response/kiro-to-claude.js
index 9118b9cb..d9fc0aab 100644
--- a/open-sse/translator/response/kiro-to-claude.js
+++ b/open-sse/translator/response/kiro-to-claude.js
@@ -48,9 +48,9 @@ function convertFinishReason(reason) {
  */
 // Kiro only accepts sanitized tool names; the request translator leaves the
 // reverse map on the stream state so calls come back under the client's names.
-function restoreToolName(state, name) {
+function restoreToolName(stateOrData, name) {
   const raw = name || "";
-  const map = state?.toolNameMap;
+  const map = stateOrData?.toolNameMap || stateOrData?._toolNameMap;
   return map && typeof map.get === "function" && map.has(raw) ? map.get(raw) : raw;
 }
 
@@ -254,7 +254,7 @@ export function kiroToClaudeNonStreaming(data) {
       content.push({
         type: "tool_use",
         id: tc.id || `toolu_${Date.now()}`,
-        name: restoreToolName(state, tc.function?.name),
+        name: restoreToolName(data, tc.function?.name),
         input,
       });
     }
diff --git a/tests/translator/agent-client-fixes.test.js b/tests/translator/agent-client-fixes.test.js
index 3f4e7cd7..6004db80 100644
--- a/tests/translator/agent-client-fixes.test.js
+++ b/tests/translator/agent-client-fixes.test.js
@@ -79,12 +79,14 @@ describe("tool-result images reach OpenAI-format upstreams", () => {
 
 describe("Kiro tool names round-trip", () => {
   it("returns the sanitized→original map on the translated body", () => {
-    const out = translateRequest(FORMATS.CLAUDE, FORMATS.KIRO, "claude-sonnet-4.5", screenshotTurn(), true, null, "kiro");
+    const body = screenshotTurn();
+    body.tools = [{ name: "mcp.browser.computer", description: "browser", input_schema: { type: "object", properties: {} } }];
+    const out = translateRequest(FORMATS.CLAUDE, FORMATS.KIRO, "claude-sonnet-4.5", body, true, null, "kiro");
     expect(out._toolNameMap).toBeInstanceOf(Map);
-    expect(out._toolNameMap.get("mcp_browser_computer")).toBe("mcp__browser__computer");
+    expect(out._toolNameMap.get("mcp_browser_computer")).toBe("mcp.browser.computer");
     const wire = JSON.parse(JSON.stringify(out.conversationState));
     expect(JSON.stringify(wire)).toContain("mcp_browser_computer");
-    expect(JSON.stringify(wire)).not.toContain("mcp__browser__computer");
+    expect(JSON.stringify(wire)).not.toContain("mcp.browser.computer");
   });
 
   it("omits the map when no name changed", () => {
diff --git a/tests/translator/kiro-tool-name-roundtrip.test.js b/tests/translator/kiro-tool-name-roundtrip.test.js
new file mode 100644
index 00000000..a8f151ad
--- /dev/null
+++ b/tests/translator/kiro-tool-name-roundtrip.test.js
@@ -0,0 +1,110 @@
+import { describe, it, expect } from "vitest";
+import { normalizeKiroToolSpecs } from "../../open-sse/translator/concerns/kiroConversation.js";
+import { openaiToKiroRequest } from "../../open-sse/translator/request/openai-to-kiro.js";
+import { claudeToKiroRequest } from "../../open-sse/translator/request/claude-to-kiro.js";
+import { kiroToOpenAIResponse } from "../../open-sse/translator/response/kiro-to-openai.js";
+import { kiroToClaudeResponse, kiroToClaudeNonStreaming } from "../../open-sse/translator/response/kiro-to-claude.js";
+
+describe("Kiro tool name normalization and roundtrip", () => {
+  it("preserves consecutive underscores like mcp__gitea__search_repos without collapsing", () => {
+    const { specs, nameMap } = normalizeKiroToolSpecs([
+      { name: "mcp__gitea__search_repos", description: "Search Gitea" },
+    ]);
+    expect(specs).toHaveLength(1);
+    expect(specs[0].toolSpecification.name).toBe("mcp__gitea__search_repos");
+    expect(nameMap.get("mcp__gitea__search_repos")).toBe("mcp__gitea__search_repos");
+  });
+
+  it("builds _toolNameMap for illegal characters and deduplicates colliding names", () => {
+    const tools = [
+      { name: "my.tool/search", description: "tool 1" },
+      { name: "my_tool_search", description: "tool 2" },
+    ];
+    const openaiPayload = openaiToKiroRequest("claude-sonnet-4.6", {
+      tools: tools.map((t) => ({ type: "function", function: t })),
+      messages: [{ role: "user", content: "hello" }],
+    }, true, {});
+
+    expect(openaiPayload._toolNameMap).toBeInstanceOf(Map);
+    // my.tool/search cleaned to my_tool_search. Since my_tool_search comes next, it becomes my_tool_search_2
+    expect(openaiPayload._toolNameMap.get("my_tool_search")).toBe("my.tool/search");
+
+    const claudePayload = claudeToKiroRequest("claude-sonnet-4.6", {
+      tools,
+      messages: [{ role: "user", content: "hello" }],
+    }, true, {});
+
+    expect(claudePayload._toolNameMap).toBeInstanceOf(Map);
+    expect(claudePayload._toolNameMap.get("my_tool_search")).toBe("my.tool/search");
+  });
+
+  it("does not attach _toolNameMap when all tool names are legal and unchanged", () => {
+    const tools = [
+      { name: "mcp__gitea__search_repos", description: "Search Gitea" },
+      { name: "bash_exec", description: "Run bash" },
+    ];
+    const payload = openaiToKiroRequest("claude-sonnet-4.6", {
+      tools: tools.map((t) => ({ type: "function", function: t })),
+      messages: [{ role: "user", content: "hello" }],
+    }, true, {});
+
+    expect(payload._toolNameMap).toBeUndefined();
+  });
+
+  it("restores original tool name in kiroToOpenAIResponse when state.toolNameMap is present", () => {
+    const state = {
+      toolNameMap: new Map([["my_tool_search", "my.tool/search"]]),
+    };
+    const event = {
+      toolUseEvent: {
+        toolUseId: "call_123",
+        name: "my_tool_search",
+        input: { q: "test" },
+      },
+    };
+    const chunk = kiroToOpenAIResponse(event, state);
+    expect(chunk).not.toBeNull();
+    expect(chunk.choices[0].delta.tool_calls[0].function.name).toBe("my.tool/search");
+  });
+
+  it("restores original tool name in kiroToClaudeResponse streaming when state.toolNameMap is present", () => {
+    const state = {
+      toolNameMap: new Map([["my_tool_search", "my.tool/search"]]),
+      toolCalls: new Map(),
+      nextBlockIndex: 0,
+    };
+    const chunk = {
+      id: "chatcmpl-1",
+      choices: [{
+        delta: {
+          tool_calls: [{
+            index: 0,
+            id: "call_123",
+            type: "function",
+            function: { name: "my_tool_search", arguments: "" },
+          }],
+        },
+      }],
+    };
+    const events = kiroToClaudeResponse(chunk, state);
+    const startEvent = events.find((e) => e.type === "content_block_start");
+    expect(startEvent).toBeDefined();
+    expect(startEvent.content_block.name).toBe("my.tool/search");
+  });
+
+  it("restores original tool name in kiroToClaudeNonStreaming when toolNameMap is present", () => {
+    const data = {
+      choices: [{
+        message: {
+          tool_calls: [{
+            id: "call_123",
+            function: { name: "my_tool_search", arguments: "{}" },
+          }],
+        },
+      }],
+      toolNameMap: new Map([["my_tool_search", "my.tool/search"]]),
+    };
+    const result = kiroToClaudeNonStreaming(data);
+    expect(result.content[0].name).toBe("my.tool/search");
+  });
+});