diff --git a/public/index.html b/public/index.html
index 48aa019..4c78641 100644
--- a/public/index.html
+++ b/public/index.html
@@ -291,13 +291,9 @@
             <label class="checkbox-label"><input type="checkbox" id="config-exists" checked> 该配置项当前存在/生效</label>
           </div>
         </div>
-        <div class="form-group">
-          <label>说明 <span class="required">*</span></label>
-          <textarea id="config-description" rows="2" placeholder="配置项用途说明"></textarea>
-        </div>
-        <div class="form-group">
-          <label>用途 <span class="hint">（规划模式）</span></label>
-          <textarea id="config-purpose" rows="2" placeholder="详细用途描述"></textarea>
+<div class="form-group">
+          <label>说明 <span class="required">*</span></label>
+          <textarea id="config-description" rows="2" placeholder="配置项用途说明"></textarea>
         </div>
       </div>
       <div class="modal-footer">
diff --git a/public/js/app.js b/public/js/app.js
index 65286c1..14a12f5 100644
--- a/public/js/app.js
+++ b/public/js/app.js
@@ -377,8 +377,7 @@ function openConfigModal(config, readonly) {
       : "配置值";
   document.getElementById("config-type").value = config ? config.type : "string";
   document.getElementById("config-value-range").value = config ? config.valueRange || "" : "";
-  document.getElementById("config-description").value = config ? config.description : "";
-  document.getElementById("config-purpose").value = config ? config.purpose || "" : "";
+document.getElementById("config-description").value = config ? config.description : "";
   document.getElementById("config-required").checked = config ? config.required === true : false;
   document.getElementById("config-exists").checked = config ? config.exists !== false : true;
   document.getElementById("config-range-preset").value = "";
@@ -400,8 +399,8 @@ function updateRangePresetVisibility() {
 
 /**
  * 根据模式和是否只读查看，设置配置模态框各字段的可编辑性
- * 规划模式：结构字段(类型/说明/用途/范围/键名/维度)可改，值不可改
- * 编辑模式：值可改，已有项的结构字段锁定
+* 规划模式：结构字段(类型/说明/范围/键名/维度)可改，值不可改
+ * 编辑模式：值、说明可改，已有项的其他结构字段锁定
  * 只读查看：全部禁用
  * @param {boolean} readonly - 是否只读查看
  * @returns {void}
@@ -409,8 +408,8 @@ function updateRangePresetVisibility() {
 function applyFieldPermissions(readonly) {
   const structFields = [
     "config-key", "config-type", "config-value-range", "config-required",
-    "config-default-value",
-    "config-description", "config-purpose",
+"config-default-value",
+    "config-description",
     "config-idc", "config-environment", "config-group",
   ];
   const valueField = "config-value";
@@ -444,10 +443,8 @@ function applyFieldPermissions(readonly) {
     const isNew = !state.editingConfigId;
     document.getElementById("config-type").disabled = !isNew;
     document.getElementById("config-value-range").disabled = !isNew;
-    document.getElementById("config-required").disabled = !isNew;
-    document.getElementById("config-default-value").disabled = !isNew;
-    document.getElementById("config-description").disabled = !isNew;
-    document.getElementById("config-purpose").disabled = !isNew;
+document.getElementById("config-required").disabled = !isNew;
+    document.getElementById("config-default-value").disabled = !isNew;
     document.getElementById("config-key").disabled = false;
     document.getElementById("config-idc").disabled = false;
     document.getElementById("config-environment").disabled = false;
@@ -474,9 +471,8 @@ function collectConfigForm() {
     defaultValue: document.getElementById("config-default-value").value,
     required: document.getElementById("config-required").checked,
     exists: document.getElementById("config-exists").checked,
-    description: document.getElementById("config-description").value.trim(),
-    purpose: document.getElementById("config-purpose").value.trim(),
-  };
+description: document.getElementById("config-description").value.trim(),
+  };
 }
 
 /**
diff --git a/src/mcp/tools.js b/src/mcp/tools.js
index 11a94b8..d8f0a13 100644
--- a/src/mcp/tools.js
+++ b/src/mcp/tools.js
@@ -401,7 +401,7 @@ function createMcpServer() {
     "update_config",
     {
       description:
-        "修改配置项（只读模式下禁止）。plan 模式可修改 type/description/purpose/valueRange/required/key/维度；edit 模式可修改 value/exists/key/维度。可仅传需修改的字段。",
+        "修改配置项（只读模式下禁止）。plan 模式可修改 type/description/purpose/valueRange/required/key/维度；edit 模式可修改 value/exists/description/key/维度。可仅传需修改的字段。",
       inputSchema: {
         projectId: z.string().describe("项目 ID"),
         configId: z.string().describe("配置项 ID"),
diff --git a/src/services/configService.js b/src/services/configService.js
index 779ee04..072d1c4 100644
--- a/src/services/configService.js
+++ b/src/services/configService.js
@@ -238,8 +238,8 @@ function validateStructure(config, project) {
 
 /**
  * 更新配置项
- * 规划模式：可修改 type、description、purpose、valueRange、required
- * 编辑模式：可修改 value、exists
+* 规划模式：可修改 type、description、purpose、valueRange、required
+ * 编辑模式：可修改 value、exists、description
  * 只读模式：不可修改
  * @param {string} projectId - 项目 ID
  * @param {string} configId - 配置项 ID
@@ -278,12 +278,13 @@ async function updateConfig(projectId, configId, data, mode) {
     if (data.environment !== undefined) config.environment = data.environment;
     if (data.group !== undefined) config.group = data.group;
     validateStructure(config, project);
-  } else if (mode === "edit") {
-    // 编辑模式：修改值与存在性
-    if (data.value !== undefined) config.value = data.value;
-    if (data.exists !== undefined) config.exists = data.exists !== false;
-    validateEditValue(config);
-    // 编辑模式下也可以修改 key 和维度（路径调整）
+} else if (mode === "edit") {
+    // 编辑模式：修改值、存在性与说明
+    if (data.value !== undefined) config.value = data.value;
+    if (data.exists !== undefined) config.exists = data.exists !== false;
+    validateEditValue(config);
+    // 编辑模式下也可以修改 key 和维度（路径调整）
+    if (data.description !== undefined) config.description = String(data.description ?? "").trim();
     if (data.key !== undefined) config.key = normalizeKey(data.key);
     if (data.idc !== undefined) config.idc = data.idc;
     if (data.environment !== undefined) config.environment = data.environment;
diff --git a/test/mcp.test.js b/test/mcp.test.js
index 93a3fff..db08156 100644
--- a/test/mcp.test.js
+++ b/test/mcp.test.js
@@ -128,6 +128,38 @@ test("readonly 模式下拒绝项目/配置写操作，切换回 edit 后恢复"
   await callTool("set_mode", { mode: "edit" });
 });
 
+test("edit 模式下可以修改配置说明", async () => {
+  await callTool("set_mode", { mode: "edit" });
+
+  const { text: createText } = await callTool("create_project", { name: "MCP-Unittest-Desc" });
+  const project = JSON.parse(createText.match(/\{[\s\S]*\}/)[0]);
+
+  const cfg = await callTool("create_config", {
+    projectId: project.id,
+    key: "db/host",
+    description: "原始说明",
+    value: "localhost",
+  });
+  const cfgObj = JSON.parse(cfg.text.match(/\{[\s\S]*\}/)[0]);
+
+  const updated = await callTool("update_config", {
+    projectId: project.id,
+    configId: cfgObj.id,
+    description: "新的说明",
+  });
+  assert.ok(!updated.isError, "edit 模式下应允许修改说明");
+  const updatedObj = JSON.parse(updated.text.match(/\{[\s\S]*\}/)[0]);
+  assert.strictEqual(updatedObj.description, "新的说明");
+  assert.strictEqual(updatedObj.value, "localhost", "仅改说明，值不应变化");
+
+  // 清理测试项目
+  const delProject = await callTool("delete_project", { projectId: project.id });
+  const confirmProject = await callTool("confirm_delete_project", {
+    confirmation_token: delProject.structuredContent.confirmation_token,
+  });
+  assert.strictEqual(confirmProject.structuredContent.status, "deleted");
+});
+
 test("配置删除同样为两步式确认", async () => {
   const { text: createText } = await callTool("create_project", { name: "MCP-Unittest-Cfg" });
   const project = JSON.parse(createText.match(/\{[\s\S]*\}/)[0]);