diff --git a/clients/terminal/tui/renderers/__init__.py b/clients/terminal/tui/renderers/__init__.py
index cf33a5d..5ba71c3 100644
--- a/clients/terminal/tui/renderers/__init__.py
+++ b/clients/terminal/tui/renderers/__init__.py
@@ -18,9 +18,10 @@
     reg.register(subagent.SpawnAgentResultRenderer())
     reg.register(todo.TodoStartedRenderer())
     reg.register(todo.TodoResultRenderer())
+    # filesystem-specific renderers must be checked before the generic tool
+    # renderers (first accepting renderer wins).
+    reg.register(filesystem.FilesystemToolStartedRenderer())
     reg.register(tool.ToolStartedRenderer())
-    # filesystem-specific result renderer must be checked before the generic
-    # ToolResultRenderer (first accepting renderer wins).
     reg.register(filesystem.FilesystemToolResultRenderer())
     reg.register(tool.ToolResultRenderer())
     reg.register(error.ErrorRenderer())
diff --git a/clients/terminal/tui/renderers/filesystem.py b/clients/terminal/tui/renderers/filesystem.py
index d7dbfc1..0ea5922 100644
--- a/clients/terminal/tui/renderers/filesystem.py
+++ b/clients/terminal/tui/renderers/filesystem.py
@@ -1,12 +1,17 @@
-"""Styled renderer for ``filesystem`` tool-call results.
+"""Styled renderers for ``filesystem`` tool events.
 
-The filesystem tool embeds structured output (unified diffs, directory listings,
-grep matches) as plain text in ``ToolResult.output``. This renderer detects the
-action via ``args.action`` and restyles the output — diff highlighting, listing
-layout, grep match highlighting — without touching the tool or the WebSocket
-protocol. Unknown / not-yet-styled actions fall back to the generic plain
-rendering used by :class:`ToolResultRenderer`.
-"""
+Two renderers:
+
+* :class:`FilesystemToolStartedRenderer` — restyles the ``tool_started`` card:
+  the action and primary path go into the title (``→ filesystem read
+  src/main.py``), and the body shows the key arguments compactly instead of a
+  full JSON dump, so large ``content`` / ``old`` / ``new`` values no longer
+  flood the card.
+* :class:`FilesystemToolResultRenderer` — restyles the ``tool_call`` result
+  (diff highlighting, listing layout, grep match highlighting, read/info/find
+  formatting).
+
+Neither touches the filesystem tool, the WebSocket protocol, or events. """
 
 from __future__ import annotations
 
@@ -326,4 +331,105 @@
             out.append(m.group(0), style=theme.accent.hex)
             last = m.end()
         if last < len(text):
-            out.append(text[last:], style=theme.text.hex)
\ No newline at end of file
+            out.append(text[last:], style=theme.text.hex)
+
+# Actions whose title carries "path → destination".
+_DEST_ACTIONS = {"move", "copy", "diff"}
+_PREVIEW_MAX = 60
+
+
+def _preview(s: str | None, max_len: int = _PREVIEW_MAX) -> str:
+    """Shorten a string to its first line plus a ``(+N lines)`` hint."""
+    if not s:
+        return '""'
+    lines = s.splitlines()
+    first = lines[0]
+    more = len(lines) - 1
+    if len(first) > max_len:
+        first = first[: max_len - 1] + "…"
+    if more > 0:
+        return f'"{first}" … (+{more} lines)'
+    return f'"{first}"'
+
+
+class FilesystemToolStartedRenderer(ContentRenderer):
+    """Styled ``tool_started`` card for ``filesystem``.
+
+    Title: ``→ filesystem <action> <path>`` (plus ``→ <destination>`` for
+    move/copy/diff). Body: a compact, human-readable summary of the key
+    arguments per action — large ``content`` / ``old`` / ``new`` /
+    ``instruction`` / ``question`` values are previewed, not dumped in full.
+    """
+
+    def accepts(self, msg: dict) -> bool:
+        return msg.get("type") == "tool_started" and msg.get("tool") == "filesystem"
+
+    def render(self, msg: dict) -> RenderableType:
+        theme = get_active_theme()
+        args = msg.get("args") or {}
+        action = args.get("action", "?")
+        path = args.get("path")
+
+        title = f"→ filesystem {action}"
+        if path:
+            title += f" {path}"
+        if action in _DEST_ACTIONS and args.get("destination"):
+            title += f" → {args['destination']}"
+
+        body = self._summarize(action, args, theme)
+        panel = Panel(
+            body if body.plain else Text(""),
+            title=title,
+            title_align="left",
+            border_style=theme.tool_border.hex,
+            box=ROUNDED,
+        )
+        if bool(msg.get("is_subagent", False)):
+            return Padding(panel, (0, 0, 0, 2))
+        return panel
+
+    def _summarize(self, action: str, args: dict, theme: Theme) -> Text:
+        out = Text()
+
+        def kv(key: str, value: str, value_style: str = theme.text.hex) -> None:
+            if out.plain:
+                out.append("\n")
+            out.append(key, style=theme.text_dim.hex)
+            out.append(": ", style=theme.text_dim.hex)
+            out.append(str(value), style=value_style)
+
+        if action == "read":
+            offset = args.get("offset")
+            limit = args.get("limit")
+            if offset is not None or limit is not None:
+                kv("range", f"{offset if offset is not None else 1}–{limit if limit is not None else 'end'}")
+            if args.get("numbered"):
+                kv("numbered", "true")
+        elif action in {"write", "append"}:
+            kv("content", _preview(args.get("content", "")))
+        elif action == "edit":
+            kv("old", _preview(args.get("old", "")))
+            kv("new", _preview(args.get("new", "")))
+        elif action == "edit_lines":
+            ops = args.get("operations") or []
+            kinds = [str(o.get("op", "?")) for o in ops[:5]]
+            tail = " …" if len(ops) > 5 else ""
+            kv("operations", f"{len(ops)}: {', '.join(kinds)}{tail}" if ops else "0")
+        elif action == "smart_edit":
+            kv("instruction", _preview(args.get("instruction", "")))
+        elif action == "list":
+            if args.get("recursive"):
+                kv("recursive", "true")
+        elif action in {"find", "find_up"}:
+            kv("pattern", str(args.get("pattern", "")))
+        elif action == "grep":
+            kv("pattern", str(args.get("pattern", "")))
+            if args.get("glob"):
+                kv("glob", str(args.get("glob")))
+            if args.get("regex"):
+                kv("regex", "true")
+        elif action == "query":
+            kv("question", _preview(args.get("question", "")))
+        # move/copy/diff: destination is in the title.
+        # info/delete/mkdir/exists: only the path, which is in the title.
+        return out
diff --git a/tests/clients/test_filesystem_renderer.py b/tests/clients/test_filesystem_renderer.py
index 6de92cc..dfe4ff2 100644
--- a/tests/clients/test_filesystem_renderer.py
+++ b/tests/clients/test_filesystem_renderer.py
@@ -1,11 +1,14 @@
-"""Tests for the filesystem tool-call result renderer (diff / list / grep)."""
+"""Tests for the filesystem tool renderers (tool_started + tool_call result)."""
 
 from __future__ import annotations
 
 from rich.console import Console
 from rich.text import Text
 
-from clients.terminal.tui.renderers.filesystem import FilesystemToolResultRenderer
+from clients.terminal.tui.renderers.filesystem import (
+    FilesystemToolResultRenderer,
+    FilesystemToolStartedRenderer,
+)
 from clients.terminal.tui.themes import get_active_theme, set_active_theme
 
 
@@ -565,4 +568,163 @@
         {"type": "tool_call", "tool": "filesystem", "args": {"action": "read"},
          "result": "x", "success": True, "is_subagent": False}
     )
-    assert any(line.startswith("╭") for line in _render_text(renderable).splitlines())
\ No newline at end of file
+    assert any(line.startswith("╭") for line in _render_text(renderable).splitlines())
+
+# ── tool_started ──────────────────────────────────────────────────────────────
+
+
+def _started_msg(args: dict, **extra) -> dict:
+    msg = {"type": "tool_started", "tool": "filesystem", "args": args}
+    msg.update(extra)
+    return msg
+
+
+def test_started_accepts_filesystem_only() -> None:
+    renderer = FilesystemToolStartedRenderer()
+    assert renderer.accepts(_started_msg({"action": "read", "path": "a.py"}))
+    assert not renderer.accepts({"type": "tool_started", "tool": "code_exec", "args": {}})
+    assert not renderer.accepts({"type": "tool_call", "tool": "filesystem", "args": {}})
+
+
+def test_started_title_carries_action_and_path() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(_started_msg({"action": "read", "path": "src/main.py"}))
+    title = str(panel.title)
+    assert "filesystem" in title
+    assert "read" in title
+    assert "src/main.py" in title
+
+
+def test_started_title_carries_destination_for_move_copy_diff() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    move = renderer.render(_started_msg({"action": "move", "path": "a.py", "destination": "b.py"}))
+    assert "→" in str(move.title)
+    assert "b.py" in str(move.title)
+    diff = renderer.render(_started_msg({"action": "diff", "path": "a.py", "destination": "b.py"}))
+    assert "b.py" in str(diff.title)
+    # Non-destination actions do not add the arrow.
+    read = renderer.render(_started_msg({"action": "read", "path": "a.py", "destination": "x"}))
+    assert "→ x" not in str(read.title)
+
+
+def test_started_info_has_empty_body() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(_started_msg({"action": "info", "path": "a.py"}))
+    body = _body(panel)
+    assert isinstance(body, Text)
+    assert body.plain == ""
+
+
+def test_started_read_shows_range_and_numbered() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(
+        _started_msg({"action": "read", "path": "a.py", "offset": 5, "limit": 10, "numbered": True})
+    )
+    body = _body(panel)
+    assert "range" in body.plain
+    assert "5–10" in body.plain
+    assert "numbered" in body.plain
+
+
+def test_started_write_previews_multiline_content() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(
+        _started_msg({"action": "write", "path": "a.py", "content": "line1\nline2\nline3\n"})
+    )
+    body = _body(panel)
+    assert '"line1"' in body.plain
+    assert "(+2 lines)" in body.plain
+    # Full content is not dumped.
+    assert "line3" not in body.plain
+
+
+def test_started_edit_previews_old_and_new() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(
+        _started_msg({"action": "edit", "path": "a.py", "old": "foo", "new": "bar\nbaz"})
+    )
+    body = _body(panel)
+    assert "old" in body.plain
+    assert "new" in body.plain
+    assert '"foo"' in body.plain
+    assert '"bar"' in body.plain
+    assert "(+1 lines)" in body.plain
+
+
+def test_started_edit_lines_summarizes_operations() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    ops = [
+        {"op": "replace", "start": 1, "end": 1, "content": "x"},
+        {"op": "delete", "start": 5, "end": 5},
+        {"op": "insert", "after": 7, "content": "y"},
+    ]
+    panel = renderer.render(_started_msg({"action": "edit_lines", "path": "a.py", "operations": ops}))
+    body = _body(panel)
+    assert "operations" in body.plain
+    assert "3:" in body.plain
+    assert "replace" in body.plain
+    assert "delete" in body.plain
+
+
+def test_started_grep_shows_pattern_glob_regex() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(
+        _started_msg({"action": "grep", "path": "src", "pattern": "TODO", "glob": "*.py", "regex": True})
+    )
+    body = _body(panel)
+    assert "pattern" in body.plain
+    assert "TODO" in body.plain
+    assert "glob" in body.plain
+    assert "*.py" in body.plain
+    assert "regex" in body.plain
+
+
+def test_started_smart_edit_previews_instruction() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(
+        _started_msg({"action": "smart_edit", "path": "a.py", "instruction": "rename foo to bar"})
+    )
+    body = _body(panel)
+    assert "instruction" in body.plain
+    assert "rename foo to bar" in body.plain
+
+
+def test_started_query_previews_question() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(
+        _started_msg({"action": "query", "path": "a.py", "question": "What does calculate() return?"})
+    )
+    body = _body(panel)
+    assert "question" in body.plain
+    assert "calculate()" in body.plain
+
+
+def test_started_subagent_is_indented() -> None:
+    set_active_theme("gnexus-dark")
+    renderer = FilesystemToolStartedRenderer()
+    renderable = renderer.render(
+        _started_msg({"action": "read", "path": "a.py"}, is_subagent=True)
+    )
+    assert any(line.startswith("  ") for line in _render_text(renderable).splitlines())
+
+
+def test_started_body_keys_are_dim() -> None:
+    set_active_theme("gnexus-dark")
+    theme = get_active_theme()
+    renderer = FilesystemToolStartedRenderer()
+    panel = renderer.render(_started_msg({"action": "grep", "path": "src", "pattern": "TODO"}))
+    body = _body(panel)
+    assert isinstance(body, Text)
+    assert _span_styles_at(body, "pattern") == {theme.text_dim.hex}
+    # Pattern value is in text.
+    assert theme.text.hex in _span_styles_at(body, "TODO")