diff --git a/apps/desktop/src/lib/__tests__/ai/ai.spec.ts b/apps/desktop/src/lib/__tests__/ai/ai.spec.ts
index 727861465f..b51216a140 100644
--- a/apps/desktop/src/lib/__tests__/ai/ai.spec.ts
+++ b/apps/desktop/src/lib/__tests__/ai/ai.spec.ts
@@ -77,6 +77,26 @@ describe("AI SQL dialect prompt", () => {
     await setLocale("en");
   });
 
+  it("gives Redis agents database and key-scan safety guidance", () => {
+    const prompt = buildSystemPrompt("general", context({ connectionName: "Redis", databaseType: "redis", database: "8", selectedDatabases: ["8"] }), "agent");
+
+    expect(prompt).toContain("Use dbx_execute_redis_command");
+    expect(prompt).toContain("db argument");
+    expect(prompt).toContain("Never send the SELECT command");
+    expect(prompt).toContain("Use SCAN, not KEYS");
+    expect(prompt).not.toContain("execute_query tool");
+    expect(prompt).not.toContain("Put SQL in a fenced");
+  });
+
+  it("keeps Redis ask mode command-oriented", () => {
+    const prompt = buildSystemPrompt("general", context({ connectionName: "Redis", databaseType: "redis", database: "8" }), "ask");
+
+    expect(prompt).toContain("Redis Ask mode");
+    expect(prompt).toContain("do not generate SELECT commands");
+    expect(prompt).not.toContain("Generate SQL and explanations only");
+    expect(buildUserPrompt("query", context({ databaseType: "redis", database: "8" }), "scan task keys", false)).toBe("scan task keys");
+  });
+
   it("keeps attached text data out of the system prompt", () => {
     const attachmentContext = context({
       csvFiles: [{ name: "orders.csv", content: "id,total\n1,42", truncated: true }],
diff --git a/apps/desktop/src/lib/ai/ai.ts b/apps/desktop/src/lib/ai/ai.ts
index b61ab33c88..375a63c639 100644
--- a/apps/desktop/src/lib/ai/ai.ts
+++ b/apps/desktop/src/lib/ai/ai.ts
@@ -275,8 +275,8 @@ export async function runAgentStream(input: AiRequestInput, history: api.AiMessa
 export function buildUserPrompt(action: AiAction, context: AiContext, instruction: string, isZh: boolean): string {
   const userRequest = instruction.trim() || (isZh ? "（无额外说明）" : "(No extra instruction provided.)");
   const attachedTextData = formatAttachedTextData(context, isZh);
-  if (isVectorDbType(context.databaseType)) {
-    // Vector databases: skip SQL action instructions, only send the user's request
+  if (isVectorDbType(context.databaseType) || context.databaseType === "redis") {
+    // Non-SQL databases use their system prompt for command guidance.
     return [userRequest, attachedTextData].filter(Boolean).join("\n\n");
   }
   const skill = aiSkillForAction(action);
@@ -315,6 +315,9 @@ export function buildSystemPrompt(action: AiAction, context: AiContext, mode: Ai
   if (isVectorDbType(context.databaseType)) {
     return buildVectorSystemPrompt(context, mode, custom);
   }
+  if (context.databaseType === "redis") {
+    return buildRedisSystemPrompt(context, mode, custom);
+  }
   const schema = formatSchema(context);
   const resultPreview = context.lastResultPreview ? `\nLast result preview:\n${context.lastResultPreview}\n` : "";
   const lastError = context.lastError ? `\nLast error:\n${context.lastError}\n` : "";
@@ -365,6 +368,35 @@ export function buildSystemPrompt(action: AiAction, context: AiContext, mode: Ai
   return lines.filter(Boolean).join("\n");
 }
 
+function buildRedisSystemPrompt(context: AiContext, mode: AiAssistantMode, custom?: CustomPromptContext): string {
+  const isZh = isChineseLocale(currentLocale());
+  const resultPreview = context.lastResultPreview ? `\nLast result preview:\n${context.lastResultPreview}\n` : "";
+  const lastError = context.lastError ? `\nLast error:\n${context.lastError}\n` : "";
+  const lines: string[] = [
+    isZh ? "你是 DBX 内置的 Redis 数据库助手。用中文回复。" : "You are DBX's built-in Redis database assistant. Reply in English.",
+    isZh ? "精确、保守，并严格使用 Redis 命令语义；不要生成 SQL。" : "Be precise and conservative, follow Redis command semantics, and do not generate SQL.",
+    ...buildModePromptLines(mode, isZh, context.databaseType),
+    ...buildRichContentPromptLines(isZh),
+    ...buildCustomInstructionLines(custom, isZh),
+    attachmentSafetyInstruction(isZh),
+    "",
+    "Database type: redis",
+    `Connection: ${context.connectionName}`,
+    `Database: ${context.database}`,
+    context.selectedDatabases?.length
+      ? isZh
+        ? `已选择 Redis 逻辑数据库：${JSON.stringify(context.selectedDatabases)}。调用工具时使用 db 参数指定目标数据库；MCP 授权仍然生效。`
+        : `Selected Redis logical databases: ${JSON.stringify(context.selectedDatabases)}. Use the db argument to select the target database; MCP authorization still applies.`
+      : "",
+    "",
+    `Current Redis command:\n${context.currentSql.trim() || "(empty)"}`,
+    lastError,
+    resultPreview,
+  ];
+
+  return lines.filter(Boolean).join("\n");
+}
+
 function buildBasePromptLines(isZh: boolean): string[] {
   return [
     isZh ? "你是 DBX 内置的数据库助手。用中文回复。" : "You are DBX's built-in database assistant. Reply in English.",
@@ -487,6 +519,25 @@ function buildRichContentPromptLines(isZh: boolean): string[] {
 
 function buildModePromptLines(mode: AiAssistantMode, isZh: boolean, databaseType: DatabaseType): string[] {
   const currentTimeGuidance = currentTimeToolGuidance();
+  if (databaseType === "redis") {
+    if (mode === "agent") {
+      return [
+        isZh ? "你处于 Redis Agent 模式。查询或修改 Redis 数据时使用 dbx_execute_redis_command，不要生成或执行 SQL。" : "You are in Redis Agent mode. Use dbx_execute_redis_command to query or modify Redis data; do not generate or execute SQL.",
+        isZh
+          ? "逻辑数据库必须通过工具的 db 参数选择；当前或已选择数据库也会由 DBX 作用域自动限定。禁止执行 SELECT 命令切换数据库。"
+          : "Select the logical database with the tool's db argument; DBX also scopes the current or selected database automatically. Never send the SELECT command to switch databases.",
+        isZh ? "遍历或匹配键必须使用 SCAN，不要使用 KEYS；需要完整结果时，使用返回的游标继续扫描直到游标为 0。" : "Use SCAN, not KEYS, to enumerate or match keys. For complete results, continue with the returned cursor until it reaches 0.",
+        currentTimeGuidance,
+        isZh ? "禁止不经确认直接执行 Redis 写命令；如果安全执行条件不满足，先说明原因，再给出只读替代方案。" : "Never execute Redis write commands without confirmation. If safe execution requirements are not met, explain why and provide a read-only alternative.",
+      ];
+    }
+    return [
+      isZh
+        ? "你处于 Redis Ask 模式。只生成 Redis 命令和说明，不要生成 SQL，也不要暗示已经执行或即将自动执行。需要指定逻辑数据库时说明 DB 编号，不要生成 SELECT 命令。"
+        : "You are in Redis Ask mode. Generate Redis commands and explanations only, not SQL, and do not imply that anything has run or will auto-run. State the target database number when needed; do not generate SELECT commands.",
+      currentTimeGuidance,
+    ];
+  }
   if (databaseType === "mongodb") {
     if (mode === "agent") {
       return [
diff --git a/crates/dbx-mcp/src/server.rs b/crates/dbx-mcp/src/server.rs
index b0f47accbf..503691a6c2 100644
--- a/crates/dbx-mcp/src/server.rs
+++ b/crates/dbx-mcp/src/server.rs
@@ -209,7 +209,7 @@ pub struct RemoveConnectionRequest {
 pub struct ExecuteRedisCommandRequest {
     #[serde(flatten)]
     pub selector: ConnectionSelector,
-    #[schemars(description = "Redis logical database number")]
+    #[schemars(description = "Redis logical database number. Use this argument instead of the SELECT command.")]
     #[schemars(extend("type" = "integer"))]
     pub db: Option<u32>,
     #[schemars(description = "Redis command to execute, for example GET mykey or INFO")]
@@ -1616,7 +1616,10 @@ impl DbxMcpServer {
         result
     }
 
-    #[tool(name = "dbx_execute_redis_command", description = "Execute a Redis command on a Redis connection")]
+    #[tool(
+        name = "dbx_execute_redis_command",
+        description = "Execute a Redis command on a Redis connection. Use the db argument to select a logical database instead of sending SELECT. Use SCAN rather than KEYS when enumerating keys."
+    )]
     async fn execute_redis_command(
         &self,
         Parameters(request): Parameters<ExecuteRedisCommandRequest>,
@@ -1640,6 +1643,12 @@ impl DbxMcpServer {
             Ok(argv) => argv,
             Err(error) => return tool_error("REDIS_COMMAND_BLOCKED", error),
         };
+        if argv[0].eq_ignore_ascii_case("SELECT") {
+            return tool_error(
+                "REDIS_DATABASE_SELECTION_REQUIRED",
+                "Redis SELECT is not available through MCP. Set the db argument to the logical database number instead; when db is omitted, DBX uses the current scoped database.",
+            );
+        }
         let safety = classify_command(&argv[0]);
         let policy = effective_policy_for_database_with_groups(
             &resolved.policy,
@@ -4267,6 +4276,34 @@ mod tests {
         assert!(result_text(&error).contains("DATABASE_OUT_OF_SCOPE"));
     }
 
+    #[tokio::test]
+    async fn redis_select_is_rejected_even_with_high_risk_access() {
+        let redis = connection("redis", "redis", "redis", "0");
+        let backend = Arc::new(FakeBackend {
+            connections: vec![redis],
+            policy: McpGlobalPolicy {
+                read_only: false,
+                allow_dangerous_sql: true,
+                allowed_connection_ids: None,
+                ..Default::default()
+            },
+            ..Default::default()
+        });
+        let server = DbxMcpServer::with_runtime_options(backend, McpScope::default(), false);
+
+        let result = server
+            .execute_redis_command(Parameters(ExecuteRedisCommandRequest {
+                selector: ConnectionSelector { connection_name: None, connection_id: Some("redis".to_string()) },
+                db: Some(8),
+                command: "SELECT 8".to_string(),
+            }))
+            .await;
+
+        assert_eq!(result.is_error, Some(true));
+        assert!(result_text(&result).contains("REDIS_DATABASE_SELECTION_REQUIRED"));
+        assert!(result_text(&result).contains("Set the db argument"));
+    }
+
     #[test]
     fn configured_database_allowlist_blocks_qualified_sql_references() {
         let connection = connection("sql", "sql", "mysql", "reporting");