diff --git a/java/dev/enola/ai/adk/tool/FileSystemTools.java b/java/dev/enola/ai/adk/tool/FileSystemTools.java
new file mode 100644
index 000000000..5b348a884
--- /dev/null
+++ b/java/dev/enola/ai/adk/tool/FileSystemTools.java
@@ -0,0 +1,358 @@
+/*
+ * 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.Schema;
+import com.google.adk.tools.BaseTool;
+import com.google.adk.tools.FunctionTool;
+import com.google.common.collect.ImmutableMap;
+
+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;
+import java.nio.file.Paths;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+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 final class FileSystemTools {
+    public static Map<String, BaseTool> createToolSet(FileSystemTools fileSystemTool) {
+        return ImmutableMap.of(
+                "readFile", FunctionTool.create(fileSystemTool, "readFile"),
+                "writeFile", FunctionTool.create(fileSystemTool, "writeFile"),
+                "editFile", FunctionTool.create(fileSystemTool, "editFile"),
+                "searchFiles", FunctionTool.create(fileSystemTool, "searchFiles"),
+                "listDirectory", FunctionTool.create(fileSystemTool, "listDirectory"),
+                "createDirectory", FunctionTool.create(fileSystemTool, "createDirectory"),
+                "grepFile", FunctionTool.create(fileSystemTool, "grepFile"),
+                "executeCommand", FunctionTool.create(fileSystemTool, "executeCommand"));
+    }
+
+    @Schema(description = "Lists all files and directories inside a given file system path.")
+    public Map<String, String> getListDirectory(
+            @Schema(description = "The absolute or relative path of the directory to inspect.")
+                    String path) {
+        return Tools.toMap(listDirectoryHelper(path));
+    }
+
+    @Schema(description = "Reads the entire content of a specified file.")
+    public Map<String, String> readFile(
+            @Schema(description = "The path to the file to read.") String path) {
+        return Tools.toMap(readFileHelper(path));
+    }
+
+    // TODO: add a confirmation step for overwriting files
+    // atm this will only write if the files does not exist
+    @Schema(description = "Writes content to a file.")
+    public Map<String, String> writeFile(
+            @Schema(description = "The path to the file to write.") String path,
+            @Schema(description = "The content to write to the file.") String content) {
+        return Tools.toMap(writeFileHelper(path, content));
+    }
+
+    // TODO: add a confirmation step for editing files
+    @Schema(
+            description =
+                    "Replaces a specific range of lines in a file and returns a git-style diff of"
+                            + " the changes.")
+    public Map<String, String> editFile(
+            @Schema(description = "The path to the file to edit.") String path,
+            @Schema(description = "The 1-based starting line number to replace.") int startLine,
+            @Schema(description = "The number of old lines to remove.") int linesToRemove,
+            @Schema(description = "The new lines of content to insert.") String newContent) {
+        return Tools.toMap(editFileHelper(path, startLine, linesToRemove, newContent));
+    }
+
+    @Schema(description = "Recursively searches for files and directories using a glob pattern.")
+    public Map<String, String> searchFiles(
+            @Schema(description = "The starting directory for the search.") String startPath,
+            @Schema(description = "The glob pattern to match (e.g., '**.java', '*.txt').")
+                    String glob) {
+        return Tools.toMap(searchFilesHelper(startPath, glob));
+    }
+
+    @Schema(
+            description =
+                    "Lists the contents of a directory with details like size and modification"
+                            + " date.")
+    public Map<String, String> listDirectory(
+            @Schema(description = "The path of the directory to list.") String path) {
+        return Tools.toMap(listDirectoryHelper(path));
+    }
+
+    @Schema(description = "Creates a directory, including any necessary parent directories.")
+    public Map<String, String> createDirectory(
+            @Schema(description = "The path of the directory to create.") String path) {
+        return Tools.toMap(createDirectoryHelper(path));
+    }
+
+    @Schema(description = "Searches for a text pattern within a file, like the 'grep' command.")
+    public Map<String, String> grepFile(
+            @Schema(description = "The path to the file to search.") String path,
+            @Schema(description = "The text or regex pattern to search for.") String pattern,
+            @Schema(description = "Number of context lines to show before and after a match.")
+                    int context) {
+        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 {
+            Path path = Paths.get(pathString);
+            if (!Files.isReadable(path)) return error("File is not readable: " + path);
+            return success(Files.readString(path));
+        } catch (IOException e) {
+            return error("Failed to read file: " + e.getMessage());
+        }
+    }
+
+    private SuccessOrError<String> writeFileHelper(String pathString, String content) {
+        try {
+            Path path = Paths.get(pathString);
+            if (Files.exists(path)) return error("File already exists: " + path);
+            Files.writeString(
+                    path, content, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+            return success("Successfully wrote " + content.length() + " characters to " + path);
+        } catch (IOException e) {
+            return error("Failed to write file: " + e.getMessage());
+        }
+    }
+
+    private SuccessOrError<String> editFileHelper(
+            String pathString, int startLine, int linesToRemove, String newContent) {
+        try {
+            Path path = Paths.get(pathString);
+            if (!Files.isRegularFile(path))
+                return error("File not found or not a regular file: " + path);
+
+            List<String> originalLines = Files.readAllLines(path);
+            if (startLine < 1 || startLine > originalLines.size() + 1)
+                return error("Invalid start line number.");
+
+            List<String> newLines = new ArrayList<>(originalLines);
+            int startIndex = startLine - 1;
+            int end = Math.min(startIndex + linesToRemove, newLines.size());
+            if (startIndex < end) {
+                newLines.subList(startIndex, end).clear();
+            }
+            List<String> insertLines =
+                    newContent.isEmpty() ? List.of() : Arrays.asList(newContent.split("\n"));
+            newLines.addAll(startIndex, insertLines);
+
+            Files.write(path, newLines);
+
+            // Generate Diff
+            String diff =
+                    generateDiff(
+                            pathString,
+                            String.join("\n", originalLines),
+                            String.join("\n", newLines));
+            if (diff.isEmpty()) {
+                return success("File edited, but no changes were made.");
+            }
+            return success("File successfully edited. Diff:\n" + diff);
+        } catch (IOException e) {
+            return error("Failed to edit file: " + e.getMessage());
+        }
+    }
+
+    private SuccessOrError<String> searchFilesHelper(String startPath, String glob) {
+        Path start = Paths.get(startPath);
+        PathMatcher matcher = FileSystems.getDefault().getPathMatcher("glob:" + glob);
+        try (Stream<Path> stream = Files.walk(start)) {
+            String results =
+                    stream.filter(path -> matcher.matches(path.getFileName()))
+                            .map(start::relativize)
+                            .map(Path::toString)
+                            .collect(Collectors.joining("\n"));
+            return success(results.isEmpty() ? "No matches found." : "Matches:\n" + results);
+        } catch (IOException e) {
+            return error("Error searching files: " + e.getMessage());
+        }
+    }
+
+    private SuccessOrError<String> listDirectoryHelper(String pathString) {
+        try (Stream<Path> stream = Files.list(Paths.get(pathString))) {
+            String details =
+                    stream.filter(
+                                    path ->
+                                            !path.getFileName()
+                                                    .toString()
+                                                    .startsWith(".")) // Exclude hidden files
+                            .sorted(FileSystemTools::sortPaths)
+                            .map(
+                                    path -> {
+                                        try {
+                                            BasicFileAttributes attrs =
+                                                    Files.readAttributes(
+                                                            path, BasicFileAttributes.class);
+                                            String type = attrs.isDirectory() ? "d" : "-";
+                                            long size = attrs.size();
+                                            String modified =
+                                                    DateTimeFormatter.ofPattern("MMM dd HH:mm")
+                                                            .withZone(ZoneId.systemDefault())
+                                                            .format(
+                                                                    attrs.lastModifiedTime()
+                                                                            .toInstant());
+                                            return String.format(
+                                                    "%s %10d %s %s",
+                                                    type, size, modified, path.getFileName());
+                                        } catch (IOException e) {
+                                            return path.getFileName()
+                                                    + " (error reading attributes)";
+                                        }
+                                    })
+                            .collect(Collectors.joining("\n"));
+            return success(details);
+        } catch (IOException e) {
+            return error("Could not list directory: " + e.getMessage());
+        }
+    }
+
+    private SuccessOrError<String> createDirectoryHelper(String pathString) {
+        try {
+            Path path = Files.createDirectories(Paths.get(pathString));
+            return success("Successfully created directory: " + path);
+        } catch (IOException e) {
+            return error("Could not create directory: " + e.getMessage());
+        }
+    }
+
+    private SuccessOrError<String> grepFileHelper(String pathString, String pattern, int context) {
+        try {
+            Path path = Paths.get(pathString);
+            List<String> lines = Files.readAllLines(path);
+            List<String> results = new ArrayList<>();
+            Pattern p = Pattern.compile(pattern);
+
+            for (int i = 0; i < lines.size(); i++) {
+                if (p.matcher(lines.get(i)).find()) {
+                    results.add("---");
+                    int start = Math.max(0, i - context);
+                    int end = Math.min(lines.size(), i + context + 1);
+                    for (int j = start; j < end; j++) {
+                        results.add(String.format("%d: %s", j + 1, lines.get(j)));
+                    }
+                }
+            }
+            return success(results.isEmpty() ? "No matches found." : String.join("\n", results));
+        } catch (IOException e) {
+            return error("Error reading or searching file: " + e.getMessage());
+        }
+    }
+
+    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);
+
+        if (isDirectoryA == isDirectoryB) {
+            return a.getFileName().toString().compareToIgnoreCase(b.getFileName().toString());
+        } else {
+            return isDirectoryA ? -1 : 1;
+        }
+    }
+
+    /** Normalize line endings to make replacements more consistent */
+    private String normalizeLineEndings(String text) {
+        String normalized = text.replace("\r\n", "\n");
+        return normalized.replace("\r", "\n");
+    }
+
+    /** Generate a git-style diff between original and modified content */
+    private String generateDiff(String filePath, String originalContent, String modifiedContent) {
+        originalContent = normalizeLineEndings(originalContent);
+        modifiedContent = normalizeLineEndings(modifiedContent);
+
+        StringBuilder diff = new StringBuilder();
+        diff.append("--- ").append(filePath).append("\t(original)\n");
+        diff.append("+++ ").append(filePath).append("\t(modified)\n");
+
+        String[] originalLines = originalContent.split("\n");
+        String[] modifiedLines = modifiedContent.split("\n");
+
+        if (!originalContent.equals(modifiedContent)) {
+            diff.append("@@ -1,")
+                    .append(originalLines.length)
+                    .append(" +1,")
+                    .append(modifiedLines.length)
+                    .append(" @@\n");
+            for (String line : originalLines) {
+                diff.append("-").append(line).append("\n");
+            }
+            for (String line : modifiedLines) {
+                diff.append("+").append(line).append("\n");
+            }
+        } else {
+            diff.append("No changes\n");
+        }
+        return diff.toString();
+    }
+}
diff --git a/java/dev/enola/ai/adk/tool/Tools.java b/java/dev/enola/ai/adk/tool/Tools.java
index af0651236..af9ef8d29 100644
--- a/java/dev/enola/ai/adk/tool/Tools.java
+++ b/java/dev/enola/ai/adk/tool/Tools.java
@@ -17,6 +17,7 @@
  */
 package dev.enola.ai.adk.tool;
 
+import com.google.adk.tools.BaseTool;
 import com.google.adk.tools.GoogleSearchTool;
 import com.google.common.collect.ImmutableMap;
 
@@ -40,12 +41,31 @@ public static ToolsetProvider mcp(
     }
 
     public static ToolsetProvider builtin(InstantSource instantSource) {
+        Map<String, BaseTool> fileSystemTools =
+                FileSystemTools.createToolSet(new FileSystemTools());
+
         return ToolsetProvider.immutableTools(
                 ImmutableMap.of(
                         "clock",
                         DateTimeTools.currentDateAndTimeAdkTool(new DateTimeTools(instantSource)),
                         "search_google",
-                        new GoogleSearchTool()));
+                        new GoogleSearchTool(),
+                        "list_directory",
+                        fileSystemTools.get("listDirectory"),
+                        "read_file",
+                        fileSystemTools.get("readFile"),
+                        "write_file",
+                        fileSystemTools.get("writeFile"),
+                        "edit_file",
+                        fileSystemTools.get("editFile"),
+                        "search_files",
+                        fileSystemTools.get("searchFiles"),
+                        "create_directory",
+                        fileSystemTools.get("createDirectory"),
+                        "grep_file",
+                        fileSystemTools.get("grepFile"),
+                        "execute_command",
+                        fileSystemTools.get("executeCommand")));
     }
 
     public static Map<String, String> toMap(SuccessOrError<String> soe) {
diff --git a/test/agents/builtin-tool.agent.yaml b/test/agents/builtin-tool.agent.yaml
new file mode 100644
index 000000000..49c561258
--- /dev/null
+++ b/test/agents/builtin-tool.agent.yaml
@@ -0,0 +1,12 @@
+$schema: https://enola.dev/ai/agent
+model: google://?model=gemini-2.5-flash-lite
+tools:
+  - clock
+  - read_file
+  - write_file
+  - list_directory
+  - edit_file
+  - search_files
+  - create_directory
+  - grep_file
+  - execute_command