Factor ExecTool out of FileSystemTools

docs/concepts/mcp.md

@@ -72,18 +72,6 @@ This needs `uvx` to be available; test if launching `uvx mcp-server-fetch` works
 CAUTION: This server can access local/internal IP addresses, which may represent a security risk.
 Exercise caution when using this MCP server to ensure this does not expose any sensitive data!
 
-### Filesystem
-
-```yaml
-{% include "../../test/agents/filesystem.agent.yaml" %}
-```
-
-```shell
-enola ai -a test/agents/filesystem.agent.yaml --in="list the files in $PWD"
-```
-
-This [currently](https://github.com/enola-dev/enola/issues/1631) needs `npx` to be available; test if launching `npx @modelcontextprotocol/server-filesystem` works, first.
-
 ### Git
 
 ```yaml

docs/concepts/tool.md

@@ -36,9 +36,33 @@ $ enola ai --agents=test/agents/clock.agent.yaml --in "What's the time?"
 The current date & time in CET is Saturday, August 16, 2025, 11:42 PM.
 ```
 
-## Exec
+## Exec ▶️
 
-**TODO** _Enola is planning to offer an `exec` tool. We intended to make this highly configurable._
+The `exec` tool can be used to run any command; for example, for something like this:
+
+```yaml
+{% include "../../test/agents/linux-system-summary.agent.yaml" %}
+```
+
+When this Agent is run, it would print (something like) this:
+
+```shell
+$ enola ai --agents=test/agents/linux-system-summary.agent.yaml --in="do it"
+
+Xeon CPU runs fast,
+Twelve cores, power strong.
+Memory 62GiB,
+56GiB now in use.
+One day, twenty-one mins.
+System running well,
+Tasks flow with ease.
+```
+
+!!! danger "Security Consideration"
+
+    The exec tool is very powerful, as it can run any shell command if added to an agent. This may introduce a significant security risk, as a compromised or manipulated prompt or instruction could lead to arbitrary code execution on the machine running Enola. Note that Enola (currently) does not yet double-check tool execution with the user. Please carefully consider this when using this tool.
+
+    **TODO** _We intended to make this highly configurable in the future._
 
 ## Google 🔎 🌐
 
@@ -65,6 +89,28 @@ Here's a summary of what happened on August 16, 2025:
 
 This tool is currently only supported [on Gemini](../specs/aiuri/index.md#google-ai-).
 
+## Files 📂
+
+The following built-in tools let an Agent work with the filesystem:
+
+* `read_file`: Reads the entire content of a specified file.
+* `write_file`: Writes content into a file.
+* `edit_file`: Replaces a specific range of lines in a file and returns a git-style diff of the changes.
+* `search_files`: Recursively searches for files and directories using a glob pattern.
+* `list_directory`: Lists the files and directory contents of a given directory with, with details like size and modification date.
+* `create_directory`: Creates a directory, including any necessary parent directories.
+* `grep_file`: Searches for a text pattern within a file.
+
+```shell
+enola ai -a test/agents/filesystem.agent.yaml --in="list the files in $PWD"
+```
+
+!!! danger "Security Consideration"
+
+    The filesystem related tools are very powerful, because when enabled in an agent, they can currently access the full filesystem. This may introduce a significant security risk, as a compromised or manipulated prompt or instruction could unintentionally expose data from sensitive files on the machine running Enola. Note that Enola (currently) does not yet double-check tool execution with the user. Please carefully consider this when using this tool, and only add actually required tools to agents.
+
+    **TODO** _We intended to be able to limit accessible directories (like MCP roots) in the future._
+
 ## MCP
 
 [MCP](mcp.md) allows Enola to access many thousands of other tools!

java/dev/enola/ai/adk/tool/ExecTool.java

@@ -0,0 +1,82 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Copyright 2025 The Enola <https://enola.dev> Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package dev.enola.ai.adk.tool;
+
+import static dev.enola.common.SuccessOrError.error;
+import static dev.enola.common.SuccessOrError.success;
+
+import com.google.adk.tools.Annotations;
+import com.google.adk.tools.BaseTool;
+import com.google.adk.tools.FunctionTool;
+
+import dev.enola.common.SuccessOrError;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+public class ExecTool {
+
+    // TODO Make allowed commands configurable
+
+    // TODO Use stuff from package dev.enola.common.exec
+
+    public BaseTool createTool() {
+        return FunctionTool.create(this, "executeCommand");
+    }
+
+    @Annotations.Schema(
+            description =
+                    "Executes a shell command and captures its standard output and standard error.")
+    public Map<String, String> executeCommand(
+            @Annotations.Schema(description = "The command to execute (e.g., 'ls -l').")
+                    String command) {
+        return Tools.toMap(executeCommandHelper(command));
+    }
+
+    private SuccessOrError<String> executeCommandHelper(String command) {
+        try {
+            ProcessBuilder pb = new ProcessBuilder("bash", "-c", command);
+            pb.redirectErrorStream(true); // Combine stdout and stderr
+            Process process = pb.start();
+
+            StringBuilder output = new StringBuilder();
+            try (BufferedReader reader =
+                    new BufferedReader(new InputStreamReader(process.getInputStream()))) {
+                String line;
+                while ((line = reader.readLine()) != null) {
+                    output.append(line).append("\n");
+                }
+            }
+
+            if (!process.waitFor(10, TimeUnit.SECONDS)) {
+                process.destroyForcibly();
+                return error("Command timed out after 10 seconds.");
+            }
+
+            int exitCode = process.exitValue();
+            return success(
+                    String.format(
+                            "Exit Code: %d%nOutput:%n%s", exitCode, output.toString().trim()));
+        } catch (IOException | InterruptedException e) {
+            return error("Failed to execute command: " + e.getMessage());
+        }
+    }
+}

java/dev/enola/ai/adk/tool/FileSystemTools.java

@@ -27,9 +27,7 @@
 
 import dev.enola.common.SuccessOrError;
 
-import java.io.BufferedReader;
 import java.io.IOException;
-import java.io.InputStreamReader;
 import java.nio.file.*;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -41,13 +39,14 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
-import java.util.concurrent.TimeUnit;
 import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 public class FileSystemTools {
 
+    // TODO Enforce root(s); see "root" related TODO in McpLoader
+
     public Map<String, BaseTool> createToolSet() {
         return ImmutableMap.of(
                 "read_file", FunctionTool.create(this, "readFile"),
@@ -56,8 +55,7 @@ public Map<String, BaseTool> createToolSet() {
                 "search_files", FunctionTool.create(this, "searchFiles"),
                 "list_directory", FunctionTool.create(this, "listDirectory"),
                 "create_directory", FunctionTool.create(this, "createDirectory"),
-                "grep_file", FunctionTool.create(this, "grepFile"),
-                "execute_command", FunctionTool.create(this, "executeCommand"));
+                "grep_file", FunctionTool.create(this, "grepFile"));
     }
 
     @Schema(description = "Reads the entire content of a specified file.")
@@ -121,14 +119,6 @@ public Map<String, String> grepFile(
         return Tools.toMap(grepFileHelper(path, pattern, context));
     }
 
-    @Schema(
-            description =
-                    "Executes a shell command and captures its standard output and standard error.")
-    public Map<String, String> executeCommand(
-            @Schema(description = "The command to execute (e.g., 'ls -l').") String command) {
-        return Tools.toMap(executeCommandHelper(command));
-    }
-
     // Private Helper Methods
     private SuccessOrError<String> readFileHelper(String pathString) {
         try {
@@ -275,35 +265,6 @@ private SuccessOrError<String> grepFileHelper(String pathString, String pattern,
         }
     }
 
-    private SuccessOrError<String> executeCommandHelper(String command) {
-        try {
-            ProcessBuilder pb = new ProcessBuilder("bash", "-c", command);
-            pb.redirectErrorStream(true); // Combine stdout and stderr
-            Process process = pb.start();
-
-            StringBuilder output = new StringBuilder();
-            try (BufferedReader reader =
-                    new BufferedReader(new InputStreamReader(process.getInputStream()))) {
-                String line;
-                while ((line = reader.readLine()) != null) {
-                    output.append(line).append("\n");
-                }
-            }
-
-            if (!process.waitFor(10, TimeUnit.SECONDS)) {
-                process.destroy();
-                return error("Command timed out after 10 seconds.");
-            }
-
-            int exitCode = process.exitValue();
-            return success(
-                    String.format(
-                            "Exit Code: %d%nOutput:%n%s", exitCode, output.toString().trim()));
-        } catch (IOException | InterruptedException e) {
-            return error("Failed to execute command: " + e.getMessage());
-        }
-    }
-
     private static int sortPaths(Path a, Path b) {
         boolean isDirectoryA = Files.isDirectory(a);
         boolean isDirectoryB = Files.isDirectory(b);

java/dev/enola/ai/adk/tool/Tools.java

@@ -47,6 +47,7 @@ public static ToolsetProvider builtin(InstantSource instantSource) {
                 "clock", DateTimeTools.currentDateAndTimeAdkTool(new DateTimeTools(instantSource)));
         tools.put("search_google", new GoogleSearchTool());
         tools.putAll(new FileSystemTools().createToolSet());
+        tools.put("exec", new ExecTool().createTool());
 
         return ToolsetProvider.immutableTools(tools);
     }

java/dev/enola/ai/dotagent/AgentsLoaderIntegrationTest.java

@@ -81,7 +81,7 @@ public void clock() throws IOException {
         var tools = Tools.builtin(testInstantSource);
 
         if (secretManager.getOptional(GOOGLE_AI_API_KEY_SECRET_NAME).isEmpty()) return;
-        var loader = new AgentsLoader(rp, FLASH_LITE, new GoogleLlmProvider(secretManager), tools);
+        var loader = new AgentsLoader(rp, FLASH, new GoogleLlmProvider(secretManager), tools);
         var agent = load(loader, "clock.agent.yaml");
         var agentTester = new AgentTester(agent);
 

models/enola.dev/ai/mcp.yaml

@@ -18,12 +18,6 @@
 $schema: https://enola.dev/ai/mcp/server/connections
 
 servers:
-  modelcontextprotocol/filesystem:
-    command: npx
-    args: [-y, "@modelcontextprotocol/server-filesystem"]
-    origin: https://github.com/modelcontextprotocol/servers/tree/main/src/filesystem
-    roots: true
-
   modelcontextprotocol/git:
     command: uvx
     args: [mcp-server-git]

test/agents/filesystem.agent.yaml

@@ -1,4 +1,10 @@
 $schema: https://enola.dev/ai/agent
-model: google://?model=gemini-2.5-flash-lite
+model: google://?model=gemini-2.5-flash
 tools:
-  - modelcontextprotocol/filesystem
+  - read_file
+  - write_file
+  - list_directory
+  - edit_file
+  - search_files
+  - create_directory
+  - grep_file

test/agents/linux-system-summary.agent.yaml

@@ -0,0 +1,10 @@
+$schema: https://enola.dev/ai/agent
+model: google://?model=gemini-2.5-flash
+# TODO prompt
+instruction:
+  Generate a system summary using various Linux commands and format the output as a poem.
+  For memory, do include both total as well as used, including buff/cache.
+  For uptime, run it without any options, because not all versions support.
+# TODO Limit allowed commands to e.g. only "uname -a", "df -h /", "free -m", "uptime" (or whatever)
+tools:
+  - exec