diff --git a/nanobot/agent/tools/filesystem.py b/nanobot/agent/tools/filesystem.py
index 7b0b867..02c8331 100644
--- a/nanobot/agent/tools/filesystem.py
+++ b/nanobot/agent/tools/filesystem.py
@@ -1,4 +1,4 @@
-"""File system tools: read, write, edit."""
+"""File system tools: read, write, edit, list."""
 
 import difflib
 from pathlib import Path
@@ -23,62 +23,108 @@ def _resolve_path(
     return resolved
 
 
-class ReadFileTool(Tool):
-    """Tool to read file contents."""
-
-    _MAX_CHARS = 128_000  # ~128 KB — prevents OOM from reading huge files into LLM context
+class _FsTool(Tool):
+    """Shared base for filesystem tools — common init and path resolution."""
 
     def __init__(self, workspace: Path | None = None, allowed_dir: Path | None = None):
         self._workspace = workspace
         self._allowed_dir = allowed_dir
 
+    def _resolve(self, path: str) -> Path:
+        return _resolve_path(path, self._workspace, self._allowed_dir)
+
+
+# ---------------------------------------------------------------------------
+# read_file
+# ---------------------------------------------------------------------------
+
+class ReadFileTool(_FsTool):
+    """Read file contents with optional line-based pagination."""
+
+    _MAX_CHARS = 128_000
+    _DEFAULT_LIMIT = 2000
+
     @property
     def name(self) -> str:
         return "read_file"
 
     @property
     def description(self) -> str:
-        return "Read the contents of a file at the given path."
+        return (
+            "Read the contents of a file. Returns numbered lines. "
+            "Use offset and limit to paginate through large files."
+        )
 
     @property
     def parameters(self) -> dict[str, Any]:
         return {
             "type": "object",
-            "properties": {"path": {"type": "string", "description": "The file path to read"}},
+            "properties": {
+                "path": {"type": "string", "description": "The file path to read"},
+                "offset": {
+                    "type": "integer",
+                    "description": "Line number to start reading from (1-indexed, default 1)",
+                    "minimum": 1,
+                },
+                "limit": {
+                    "type": "integer",
+                    "description": "Maximum number of lines to read (default 2000)",
+                    "minimum": 1,
+                },
+            },
             "required": ["path"],
         }
 
-    async def execute(self, path: str, **kwargs: Any) -> str:
+    async def execute(self, path: str, offset: int = 1, limit: int | None = None, **kwargs: Any) -> str:
         try:
-            file_path = _resolve_path(path, self._workspace, self._allowed_dir)
-            if not file_path.exists():
+            fp = self._resolve(path)
+            if not fp.exists():
                 return f"Error: File not found: {path}"
-            if not file_path.is_file():
+            if not fp.is_file():
                 return f"Error: Not a file: {path}"
 
-            size = file_path.stat().st_size
-            if size > self._MAX_CHARS * 4:  # rough upper bound (UTF-8 chars ≤ 4 bytes)
-                return (
-                    f"Error: File too large ({size:,} bytes). "
-                    f"Use exec tool with head/tail/grep to read portions."
-                )
+            all_lines = fp.read_text(encoding="utf-8").splitlines()
+            total = len(all_lines)
 
-            content = file_path.read_text(encoding="utf-8")
-            if len(content) > self._MAX_CHARS:
-                return content[: self._MAX_CHARS] + f"\n\n... (truncated — file is {len(content):,} chars, limit {self._MAX_CHARS:,})"
-            return content
+            if offset < 1:
+                offset = 1
+            if total == 0:
+                return f"(Empty file: {path})"
+            if offset > total:
+                return f"Error: offset {offset} is beyond end of file ({total} lines)"
+
+            start = offset - 1
+            end = min(start + (limit or self._DEFAULT_LIMIT), total)
+            numbered = [f"{start + i + 1}| {line}" for i, line in enumerate(all_lines[start:end])]
+            result = "\n".join(numbered)
+
+            if len(result) > self._MAX_CHARS:
+                trimmed, chars = [], 0
+                for line in numbered:
+                    chars += len(line) + 1
+                    if chars > self._MAX_CHARS:
+                        break
+                    trimmed.append(line)
+                end = start + len(trimmed)
+                result = "\n".join(trimmed)
+
+            if end < total:
+                result += f"\n\n(Showing lines {offset}-{end} of {total}. Use offset={end + 1} to continue.)"
+            else:
+                result += f"\n\n(End of file — {total} lines total)"
+            return result
         except PermissionError as e:
             return f"Error: {e}"
         except Exception as e:
-            return f"Error reading file: {str(e)}"
+            return f"Error reading file: {e}"
 
 
-class WriteFileTool(Tool):
-    """Tool to write content to a file."""
+# ---------------------------------------------------------------------------
+# write_file
+# ---------------------------------------------------------------------------
 
-    def __init__(self, workspace: Path | None = None, allowed_dir: Path | None = None):
-        self._workspace = workspace
-        self._allowed_dir = allowed_dir
+class WriteFileTool(_FsTool):
+    """Write content to a file."""
 
     @property
     def name(self) -> str:
@@ -101,22 +147,48 @@ class WriteFileTool(Tool):
 
     async def execute(self, path: str, content: str, **kwargs: Any) -> str:
         try:
-            file_path = _resolve_path(path, self._workspace, self._allowed_dir)
-            file_path.parent.mkdir(parents=True, exist_ok=True)
-            file_path.write_text(content, encoding="utf-8")
-            return f"Successfully wrote {len(content)} bytes to {file_path}"
+            fp = self._resolve(path)
+            fp.parent.mkdir(parents=True, exist_ok=True)
+            fp.write_text(content, encoding="utf-8")
+            return f"Successfully wrote {len(content)} bytes to {fp}"
         except PermissionError as e:
             return f"Error: {e}"
         except Exception as e:
-            return f"Error writing file: {str(e)}"
+            return f"Error writing file: {e}"
 
 
-class EditFileTool(Tool):
-    """Tool to edit a file by replacing text."""
+# ---------------------------------------------------------------------------
+# edit_file
+# ---------------------------------------------------------------------------
 
-    def __init__(self, workspace: Path | None = None, allowed_dir: Path | None = None):
-        self._workspace = workspace
-        self._allowed_dir = allowed_dir
+def _find_match(content: str, old_text: str) -> tuple[str | None, int]:
+    """Locate old_text in content: exact first, then line-trimmed sliding window.
+
+    Both inputs should use LF line endings (caller normalises CRLF).
+    Returns (matched_fragment, count) or (None, 0).
+    """
+    if old_text in content:
+        return old_text, content.count(old_text)
+
+    old_lines = old_text.splitlines()
+    if not old_lines:
+        return None, 0
+    stripped_old = [l.strip() for l in old_lines]
+    content_lines = content.splitlines()
+
+    candidates = []
+    for i in range(len(content_lines) - len(stripped_old) + 1):
+        window = content_lines[i : i + len(stripped_old)]
+        if [l.strip() for l in window] == stripped_old:
+            candidates.append("\n".join(window))
+
+    if candidates:
+        return candidates[0], len(candidates)
+    return None, 0
+
+
+class EditFileTool(_FsTool):
+    """Edit a file by replacing text with fallback matching."""
 
     @property
     def name(self) -> str:
@@ -124,7 +196,11 @@ class EditFileTool(Tool):
 
     @property
     def description(self) -> str:
-        return "Edit a file by replacing old_text with new_text. The old_text must exist exactly in the file."
+        return (
+            "Edit a file by replacing old_text with new_text. "
+            "Supports minor whitespace/line-ending differences. "
+            "Set replace_all=true to replace every occurrence."
+        )
 
     @property
     def parameters(self) -> dict[str, Any]:
@@ -132,40 +208,52 @@ class EditFileTool(Tool):
             "type": "object",
             "properties": {
                 "path": {"type": "string", "description": "The file path to edit"},
-                "old_text": {"type": "string", "description": "The exact text to find and replace"},
+                "old_text": {"type": "string", "description": "The text to find and replace"},
                 "new_text": {"type": "string", "description": "The text to replace with"},
+                "replace_all": {
+                    "type": "boolean",
+                    "description": "Replace all occurrences (default false)",
+                },
             },
             "required": ["path", "old_text", "new_text"],
         }
 
-    async def execute(self, path: str, old_text: str, new_text: str, **kwargs: Any) -> str:
+    async def execute(
+        self, path: str, old_text: str, new_text: str,
+        replace_all: bool = False, **kwargs: Any,
+    ) -> str:
         try:
-            file_path = _resolve_path(path, self._workspace, self._allowed_dir)
-            if not file_path.exists():
+            fp = self._resolve(path)
+            if not fp.exists():
                 return f"Error: File not found: {path}"
 
-            content = file_path.read_text(encoding="utf-8")
+            raw = fp.read_bytes()
+            uses_crlf = b"\r\n" in raw
+            content = raw.decode("utf-8").replace("\r\n", "\n")
+            match, count = _find_match(content, old_text.replace("\r\n", "\n"))
 
-            if old_text not in content:
-                return self._not_found_message(old_text, content, path)
+            if match is None:
+                return self._not_found_msg(old_text, content, path)
+            if count > 1 and not replace_all:
+                return (
+                    f"Warning: old_text appears {count} times. "
+                    "Provide more context to make it unique, or set replace_all=true."
+                )
 
-            # Count occurrences
-            count = content.count(old_text)
-            if count > 1:
-                return f"Warning: old_text appears {count} times. Please provide more context to make it unique."
+            norm_new = new_text.replace("\r\n", "\n")
+            new_content = content.replace(match, norm_new) if replace_all else content.replace(match, norm_new, 1)
+            if uses_crlf:
+                new_content = new_content.replace("\n", "\r\n")
 
-            new_content = content.replace(old_text, new_text, 1)
-            file_path.write_text(new_content, encoding="utf-8")
-
-            return f"Successfully edited {file_path}"
+            fp.write_bytes(new_content.encode("utf-8"))
+            return f"Successfully edited {fp}"
         except PermissionError as e:
             return f"Error: {e}"
         except Exception as e:
-            return f"Error editing file: {str(e)}"
+            return f"Error editing file: {e}"
 
     @staticmethod
-    def _not_found_message(old_text: str, content: str, path: str) -> str:
-        """Build a helpful error when old_text is not found."""
+    def _not_found_msg(old_text: str, content: str, path: str) -> str:
         lines = content.splitlines(keepends=True)
         old_lines = old_text.splitlines(keepends=True)
         window = len(old_lines)
@@ -177,27 +265,29 @@ class EditFileTool(Tool):
                 best_ratio, best_start = ratio, i
 
         if best_ratio > 0.5:
-            diff = "\n".join(
-                difflib.unified_diff(
-                    old_lines,
-                    lines[best_start : best_start + window],
-                    fromfile="old_text (provided)",
-                    tofile=f"{path} (actual, line {best_start + 1})",
-                    lineterm="",
-                )
-            )
+            diff = "\n".join(difflib.unified_diff(
+                old_lines, lines[best_start : best_start + window],
+                fromfile="old_text (provided)",
+                tofile=f"{path} (actual, line {best_start + 1})",
+                lineterm="",
+            ))
             return f"Error: old_text not found in {path}.\nBest match ({best_ratio:.0%} similar) at line {best_start + 1}:\n{diff}"
-        return (
-            f"Error: old_text not found in {path}. No similar text found. Verify the file content."
-        )
+        return f"Error: old_text not found in {path}. No similar text found. Verify the file content."
 
 
-class ListDirTool(Tool):
-    """Tool to list directory contents."""
+# ---------------------------------------------------------------------------
+# list_dir
+# ---------------------------------------------------------------------------
 
-    def __init__(self, workspace: Path | None = None, allowed_dir: Path | None = None):
-        self._workspace = workspace
-        self._allowed_dir = allowed_dir
+class ListDirTool(_FsTool):
+    """List directory contents with optional recursion."""
+
+    _DEFAULT_MAX = 200
+    _IGNORE_DIRS = {
+        ".git", "node_modules", "__pycache__", ".venv", "venv",
+        "dist", "build", ".tox", ".mypy_cache", ".pytest_cache",
+        ".ruff_cache", ".coverage", "htmlcov",
+    }
 
     @property
     def name(self) -> str:
@@ -205,34 +295,71 @@ class ListDirTool(Tool):
 
     @property
     def description(self) -> str:
-        return "List the contents of a directory."
+        return (
+            "List the contents of a directory. "
+            "Set recursive=true to explore nested structure. "
+            "Common noise directories (.git, node_modules, __pycache__, etc.) are auto-ignored."
+        )
 
     @property
     def parameters(self) -> dict[str, Any]:
         return {
             "type": "object",
-            "properties": {"path": {"type": "string", "description": "The directory path to list"}},
+            "properties": {
+                "path": {"type": "string", "description": "The directory path to list"},
+                "recursive": {
+                    "type": "boolean",
+                    "description": "Recursively list all files (default false)",
+                },
+                "max_entries": {
+                    "type": "integer",
+                    "description": "Maximum entries to return (default 200)",
+                    "minimum": 1,
+                },
+            },
             "required": ["path"],
         }
 
-    async def execute(self, path: str, **kwargs: Any) -> str:
+    async def execute(
+        self, path: str, recursive: bool = False,
+        max_entries: int | None = None, **kwargs: Any,
+    ) -> str:
         try:
-            dir_path = _resolve_path(path, self._workspace, self._allowed_dir)
-            if not dir_path.exists():
+            dp = self._resolve(path)
+            if not dp.exists():
                 return f"Error: Directory not found: {path}"
-            if not dir_path.is_dir():
+            if not dp.is_dir():
                 return f"Error: Not a directory: {path}"
 
-            items = []
-            for item in sorted(dir_path.iterdir()):
-                prefix = "📁 " if item.is_dir() else "📄 "
-                items.append(f"{prefix}{item.name}")
+            cap = max_entries or self._DEFAULT_MAX
+            items: list[str] = []
+            total = 0
 
-            if not items:
+            if recursive:
+                for item in sorted(dp.rglob("*")):
+                    if any(p in self._IGNORE_DIRS for p in item.parts):
+                        continue
+                    total += 1
+                    if len(items) < cap:
+                        rel = item.relative_to(dp)
+                        items.append(f"{rel}/" if item.is_dir() else str(rel))
+            else:
+                for item in sorted(dp.iterdir()):
+                    if item.name in self._IGNORE_DIRS:
+                        continue
+                    total += 1
+                    if len(items) < cap:
+                        pfx = "📁 " if item.is_dir() else "📄 "
+                        items.append(f"{pfx}{item.name}")
+
+            if not items and total == 0:
                 return f"Directory {path} is empty"
 
-            return "\n".join(items)
+            result = "\n".join(items)
+            if total > cap:
+                result += f"\n\n(truncated, showing first {cap} of {total} entries)"
+            return result
         except PermissionError as e:
             return f"Error: {e}"
         except Exception as e:
-            return f"Error listing directory: {str(e)}"
+            return f"Error listing directory: {e}"
diff --git a/nanobot/agent/tools/shell.py b/nanobot/agent/tools/shell.py
index b650930..bf1b082 100644
--- a/nanobot/agent/tools/shell.py
+++ b/nanobot/agent/tools/shell.py
@@ -42,6 +42,9 @@ class ExecTool(Tool):
     def name(self) -> str:
         return "exec"
 
+    _MAX_TIMEOUT = 600
+    _MAX_OUTPUT = 10_000
+
     @property
     def description(self) -> str:
         return "Execute a shell command and return its output. Use with caution."
@@ -53,22 +56,36 @@ class ExecTool(Tool):
             "properties": {
                 "command": {
                     "type": "string",
-                    "description": "The shell command to execute"
+                    "description": "The shell command to execute",
                 },
                 "working_dir": {
                     "type": "string",
-                    "description": "Optional working directory for the command"
-                }
+                    "description": "Optional working directory for the command",
+                },
+                "timeout": {
+                    "type": "integer",
+                    "description": (
+                        "Timeout in seconds. Increase for long-running commands "
+                        "like compilation or installation (default 60, max 600)."
+                    ),
+                    "minimum": 1,
+                    "maximum": 600,
+                },
             },
-            "required": ["command"]
+            "required": ["command"],
         }
-    
-    async def execute(self, command: str, working_dir: str | None = None, **kwargs: Any) -> str:
+
+    async def execute(
+        self, command: str, working_dir: str | None = None,
+        timeout: int | None = None, **kwargs: Any,
+    ) -> str:
         cwd = working_dir or self.working_dir or os.getcwd()
         guard_error = self._guard_command(command, cwd)
         if guard_error:
             return guard_error
-        
+
+        effective_timeout = min(timeout or self.timeout, self._MAX_TIMEOUT)
+
         env = os.environ.copy()
         if self.path_append:
             env["PATH"] = env.get("PATH", "") + os.pathsep + self.path_append
@@ -81,44 +98,46 @@ class ExecTool(Tool):
                 cwd=cwd,
                 env=env,
             )
-            
+
             try:
                 stdout, stderr = await asyncio.wait_for(
                     process.communicate(),
-                    timeout=self.timeout
+                    timeout=effective_timeout,
                 )
             except asyncio.TimeoutError:
                 process.kill()
-                # Wait for the process to fully terminate so pipes are
-                # drained and file descriptors are released.
                 try:
                     await asyncio.wait_for(process.wait(), timeout=5.0)
                 except asyncio.TimeoutError:
                     pass
-                return f"Error: Command timed out after {self.timeout} seconds"
-            
+                return f"Error: Command timed out after {effective_timeout} seconds"
+
             output_parts = []
-            
+
             if stdout:
                 output_parts.append(stdout.decode("utf-8", errors="replace"))
-            
+
             if stderr:
                 stderr_text = stderr.decode("utf-8", errors="replace")
                 if stderr_text.strip():
                     output_parts.append(f"STDERR:\n{stderr_text}")
-            
-            if process.returncode != 0:
-                output_parts.append(f"\nExit code: {process.returncode}")
-            
+
+            output_parts.append(f"\nExit code: {process.returncode}")
+
             result = "\n".join(output_parts) if output_parts else "(no output)"
-            
-            # Truncate very long output
-            max_len = 10000
+
+            # Head + tail truncation to preserve both start and end of output
+            max_len = self._MAX_OUTPUT
             if len(result) > max_len:
-                result = result[:max_len] + f"\n... (truncated, {len(result) - max_len} more chars)"
-            
+                half = max_len // 2
+                result = (
+                    result[:half]
+                    + f"\n\n... ({len(result) - max_len:,} chars truncated) ...\n\n"
+                    + result[-half:]
+                )
+
             return result
-            
+
         except Exception as e:
             return f"Error executing command: {str(e)}"
 
diff --git a/tests/test_filesystem_tools.py b/tests/test_filesystem_tools.py
new file mode 100644
index 0000000..db8f256
--- /dev/null
+++ b/tests/test_filesystem_tools.py
@@ -0,0 +1,251 @@
+"""Tests for enhanced filesystem tools: ReadFileTool, EditFileTool, ListDirTool."""
+
+import pytest
+
+from nanobot.agent.tools.filesystem import (
+    EditFileTool,
+    ListDirTool,
+    ReadFileTool,
+    _find_match,
+)
+
+
+# ---------------------------------------------------------------------------
+# ReadFileTool
+# ---------------------------------------------------------------------------
+
+class TestReadFileTool:
+
+    @pytest.fixture()
+    def tool(self, tmp_path):
+        return ReadFileTool(workspace=tmp_path)
+
+    @pytest.fixture()
+    def sample_file(self, tmp_path):
+        f = tmp_path / "sample.txt"
+        f.write_text("\n".join(f"line {i}" for i in range(1, 21)), encoding="utf-8")
+        return f
+
+    @pytest.mark.asyncio
+    async def test_basic_read_has_line_numbers(self, tool, sample_file):
+        result = await tool.execute(path=str(sample_file))
+        assert "1| line 1" in result
+        assert "20| line 20" in result
+
+    @pytest.mark.asyncio
+    async def test_offset_and_limit(self, tool, sample_file):
+        result = await tool.execute(path=str(sample_file), offset=5, limit=3)
+        assert "5| line 5" in result
+        assert "7| line 7" in result
+        assert "8| line 8" not in result
+        assert "Use offset=8 to continue" in result
+
+    @pytest.mark.asyncio
+    async def test_offset_beyond_end(self, tool, sample_file):
+        result = await tool.execute(path=str(sample_file), offset=999)
+        assert "Error" in result
+        assert "beyond end" in result
+
+    @pytest.mark.asyncio
+    async def test_end_of_file_marker(self, tool, sample_file):
+        result = await tool.execute(path=str(sample_file), offset=1, limit=9999)
+        assert "End of file" in result
+
+    @pytest.mark.asyncio
+    async def test_empty_file(self, tool, tmp_path):
+        f = tmp_path / "empty.txt"
+        f.write_text("", encoding="utf-8")
+        result = await tool.execute(path=str(f))
+        assert "Empty file" in result
+
+    @pytest.mark.asyncio
+    async def test_file_not_found(self, tool, tmp_path):
+        result = await tool.execute(path=str(tmp_path / "nope.txt"))
+        assert "Error" in result
+        assert "not found" in result
+
+    @pytest.mark.asyncio
+    async def test_char_budget_trims(self, tool, tmp_path):
+        """When the selected slice exceeds _MAX_CHARS the output is trimmed."""
+        f = tmp_path / "big.txt"
+        # Each line is ~110 chars, 2000 lines ≈ 220 KB > 128 KB limit
+        f.write_text("\n".join("x" * 110 for _ in range(2000)), encoding="utf-8")
+        result = await tool.execute(path=str(f))
+        assert len(result) <= ReadFileTool._MAX_CHARS + 500  # small margin for footer
+        assert "Use offset=" in result
+
+
+# ---------------------------------------------------------------------------
+# _find_match  (unit tests for the helper)
+# ---------------------------------------------------------------------------
+
+class TestFindMatch:
+
+    def test_exact_match(self):
+        match, count = _find_match("hello world", "world")
+        assert match == "world"
+        assert count == 1
+
+    def test_exact_no_match(self):
+        match, count = _find_match("hello world", "xyz")
+        assert match is None
+        assert count == 0
+
+    def test_crlf_normalisation(self):
+        # Caller normalises CRLF before calling _find_match, so test with
+        # pre-normalised content to verify exact match still works.
+        content = "line1\nline2\nline3"
+        old_text = "line1\nline2\nline3"
+        match, count = _find_match(content, old_text)
+        assert match is not None
+        assert count == 1
+
+    def test_line_trim_fallback(self):
+        content = "    def foo():\n        pass\n"
+        old_text = "def foo():\n    pass"
+        match, count = _find_match(content, old_text)
+        assert match is not None
+        assert count == 1
+        # The returned match should be the *original* indented text
+        assert "    def foo():" in match
+
+    def test_line_trim_multiple_candidates(self):
+        content = "  a\n  b\n  a\n  b\n"
+        old_text = "a\nb"
+        match, count = _find_match(content, old_text)
+        assert count == 2
+
+    def test_empty_old_text(self):
+        match, count = _find_match("hello", "")
+        # Empty string is always "in" any string via exact match
+        assert match == ""
+
+
+# ---------------------------------------------------------------------------
+# EditFileTool
+# ---------------------------------------------------------------------------
+
+class TestEditFileTool:
+
+    @pytest.fixture()
+    def tool(self, tmp_path):
+        return EditFileTool(workspace=tmp_path)
+
+    @pytest.mark.asyncio
+    async def test_exact_match(self, tool, tmp_path):
+        f = tmp_path / "a.py"
+        f.write_text("hello world", encoding="utf-8")
+        result = await tool.execute(path=str(f), old_text="world", new_text="earth")
+        assert "Successfully" in result
+        assert f.read_text() == "hello earth"
+
+    @pytest.mark.asyncio
+    async def test_crlf_normalisation(self, tool, tmp_path):
+        f = tmp_path / "crlf.py"
+        f.write_bytes(b"line1\r\nline2\r\nline3")
+        result = await tool.execute(
+            path=str(f), old_text="line1\nline2", new_text="LINE1\nLINE2",
+        )
+        assert "Successfully" in result
+        raw = f.read_bytes()
+        assert b"LINE1" in raw
+        # CRLF line endings should be preserved throughout the file
+        assert b"\r\n" in raw
+
+    @pytest.mark.asyncio
+    async def test_trim_fallback(self, tool, tmp_path):
+        f = tmp_path / "indent.py"
+        f.write_text("    def foo():\n        pass\n", encoding="utf-8")
+        result = await tool.execute(
+            path=str(f), old_text="def foo():\n    pass", new_text="def bar():\n    return 1",
+        )
+        assert "Successfully" in result
+        assert "bar" in f.read_text()
+
+    @pytest.mark.asyncio
+    async def test_ambiguous_match(self, tool, tmp_path):
+        f = tmp_path / "dup.py"
+        f.write_text("aaa\nbbb\naaa\nbbb\n", encoding="utf-8")
+        result = await tool.execute(path=str(f), old_text="aaa\nbbb", new_text="xxx")
+        assert "appears" in result.lower() or "Warning" in result
+
+    @pytest.mark.asyncio
+    async def test_replace_all(self, tool, tmp_path):
+        f = tmp_path / "multi.py"
+        f.write_text("foo bar foo bar foo", encoding="utf-8")
+        result = await tool.execute(
+            path=str(f), old_text="foo", new_text="baz", replace_all=True,
+        )
+        assert "Successfully" in result
+        assert f.read_text() == "baz bar baz bar baz"
+
+    @pytest.mark.asyncio
+    async def test_not_found(self, tool, tmp_path):
+        f = tmp_path / "nf.py"
+        f.write_text("hello", encoding="utf-8")
+        result = await tool.execute(path=str(f), old_text="xyz", new_text="abc")
+        assert "Error" in result
+        assert "not found" in result
+
+
+# ---------------------------------------------------------------------------
+# ListDirTool
+# ---------------------------------------------------------------------------
+
+class TestListDirTool:
+
+    @pytest.fixture()
+    def tool(self, tmp_path):
+        return ListDirTool(workspace=tmp_path)
+
+    @pytest.fixture()
+    def populated_dir(self, tmp_path):
+        (tmp_path / "src").mkdir()
+        (tmp_path / "src" / "main.py").write_text("pass")
+        (tmp_path / "src" / "utils.py").write_text("pass")
+        (tmp_path / "README.md").write_text("hi")
+        (tmp_path / ".git").mkdir()
+        (tmp_path / ".git" / "config").write_text("x")
+        (tmp_path / "node_modules").mkdir()
+        (tmp_path / "node_modules" / "pkg").mkdir()
+        return tmp_path
+
+    @pytest.mark.asyncio
+    async def test_basic_list(self, tool, populated_dir):
+        result = await tool.execute(path=str(populated_dir))
+        assert "README.md" in result
+        assert "src" in result
+        # .git and node_modules should be ignored
+        assert ".git" not in result
+        assert "node_modules" not in result
+
+    @pytest.mark.asyncio
+    async def test_recursive(self, tool, populated_dir):
+        result = await tool.execute(path=str(populated_dir), recursive=True)
+        assert "src/main.py" in result
+        assert "src/utils.py" in result
+        assert "README.md" in result
+        # Ignored dirs should not appear
+        assert ".git" not in result
+        assert "node_modules" not in result
+
+    @pytest.mark.asyncio
+    async def test_max_entries_truncation(self, tool, tmp_path):
+        for i in range(10):
+            (tmp_path / f"file_{i}.txt").write_text("x")
+        result = await tool.execute(path=str(tmp_path), max_entries=3)
+        assert "truncated" in result
+        assert "3 of 10" in result
+
+    @pytest.mark.asyncio
+    async def test_empty_dir(self, tool, tmp_path):
+        d = tmp_path / "empty"
+        d.mkdir()
+        result = await tool.execute(path=str(d))
+        assert "empty" in result.lower()
+
+    @pytest.mark.asyncio
+    async def test_not_found(self, tool, tmp_path):
+        result = await tool.execute(path=str(tmp_path / "nope"))
+        assert "Error" in result
+        assert "not found" in result
diff --git a/tests/test_tool_validation.py b/tests/test_tool_validation.py
index e67acbf..095c041 100644
--- a/tests/test_tool_validation.py
+++ b/tests/test_tool_validation.py
@@ -363,3 +363,44 @@ def test_cast_params_single_value_not_auto_wrapped_to_array() -> None:
     assert result["items"] == 5  # Not wrapped to [5]
     result = tool.cast_params({"items": "text"})
     assert result["items"] == "text"  # Not wrapped to ["text"]
+
+
+# --- ExecTool enhancement tests ---
+
+
+async def test_exec_always_returns_exit_code() -> None:
+    """Exit code should appear in output even on success (exit 0)."""
+    tool = ExecTool()
+    result = await tool.execute(command="echo hello")
+    assert "Exit code: 0" in result
+    assert "hello" in result
+
+
+async def test_exec_head_tail_truncation() -> None:
+    """Long output should preserve both head and tail."""
+    tool = ExecTool()
+    # Generate output that exceeds _MAX_OUTPUT
+    big = "A" * 6000 + "\n" + "B" * 6000
+    result = await tool.execute(command=f"echo '{big}'")
+    assert "chars truncated" in result
+    # Head portion should start with As
+    assert result.startswith("A")
+    # Tail portion should end with the exit code which comes after Bs
+    assert "Exit code:" in result
+
+
+async def test_exec_timeout_parameter() -> None:
+    """LLM-supplied timeout should override the constructor default."""
+    tool = ExecTool(timeout=60)
+    # A very short timeout should cause the command to be killed
+    result = await tool.execute(command="sleep 10", timeout=1)
+    assert "timed out" in result
+    assert "1 seconds" in result
+
+
+async def test_exec_timeout_capped_at_max() -> None:
+    """Timeout values above _MAX_TIMEOUT should be clamped."""
+    tool = ExecTool()
+    # Should not raise — just clamp to 600
+    result = await tool.execute(command="echo ok", timeout=9999)
+    assert "Exit code: 0" in result