fix: follow nextCursor when listing MCP tools

src/mcp2cli/__init__.py

@@ -2729,14 +2729,14 @@ async def _mcp_session(
     )
 
     if list_mode:
-        result = await session.list_tools()
+        all_tools = await _list_all_tools(session)
         tools = [
             {
                 "name": t.name,
                 "description": t.description or "",
                 "inputSchema": t.inputSchema or {},
             }
-            for t in result.tools
+            for t in all_tools
         ]
         commands = extract_mcp_commands(tools)
         if search_pattern:
@@ -3032,11 +3032,27 @@ def _extract_content_parts(content_list, *, attrs=("text", "data")) -> str:
     return "\n".join(parts) if parts else ""
 
 
+async def _list_all_tools(session):
+    """Fetch every tool from an MCP session, following `nextCursor` until
+    exhausted. Per the MCP spec, tools/list is paginated and page size is
+    entirely up to the server, so a single call is not guaranteed to return
+    the full tool set: https://modelcontextprotocol.io/specification/2025-06-18/server/utilities/pagination
+    """
+    tools = []
+    cursor = None
+    while True:
+        result = await session.list_tools(cursor=cursor)
+        tools.extend(result.tools)
+        cursor = result.nextCursor
+        if not cursor:
+            return tools
+
+
 async def _dispatch_list_tools(session, params):
-    result = await session.list_tools()
+    tools = await _list_all_tools(session)
     return [
         {"name": t.name, "description": t.description or "", "inputSchema": t.inputSchema or {}}
-        for t in result.tools
+        for t in tools
     ]
 
 
@@ -3517,14 +3533,14 @@ def _fetch_mcp_tools(
     tools_result: list[dict] = []
 
     async def _extract_tools(session):
-        result = await session.list_tools()
+        all_tools = await _list_all_tools(session)
         tools_result.extend(
             {
                 "name": t.name,
                 "description": t.description or "",
                 "inputSchema": t.inputSchema or {},
             }
-            for t in result.tools
+            for t in all_tools
         )
 
     async def _run():

tests/test_helpers.py

@@ -1,6 +1,7 @@
 """Tests for helper functions and data structures."""
 
 import argparse
+import asyncio
 import json
 import shutil
 
@@ -10,6 +11,7 @@
     _apply_head,
     _collect_openapi_params,
     _find_toon_cli,
+    _list_all_tools,
     _split_at_subcommand,
     _toon_encode,
     cache_key_for,
@@ -609,3 +611,53 @@ def test_body_schemaless_json_object(self):
         args = argparse.Namespace(args='{"key": "value"}', stdin=False)
         _, _, _, body, _ = _collect_openapi_params(cmd, args)
         assert body == {"args": {"key": "value"}}
+
+
+class _FakePage:
+    def __init__(self, tools, next_cursor=None):
+        self.tools = tools
+        self.nextCursor = next_cursor
+
+
+class _FakeSession:
+    """Fake MCP session whose list_tools() serves canned pages, keyed by cursor."""
+
+    def __init__(self, pages):
+        # pages: list of (cursor_expected, _FakePage) in order
+        self._pages = pages
+        self.calls = []
+
+    async def list_tools(self, cursor=None):
+        self.calls.append(cursor)
+        expected_cursor, page = self._pages[len(self.calls) - 1]
+        assert cursor == expected_cursor, (
+            f"call {len(self.calls)}: expected cursor={expected_cursor!r}, got {cursor!r}"
+        )
+        return page
+
+
+class TestListAllTools:
+    def test_single_page_no_cursor(self):
+        """A server that never sets nextCursor is fetched in exactly one call."""
+        session = _FakeSession([(None, _FakePage(["a", "b"], next_cursor=None))])
+        tools = asyncio.run(_list_all_tools(session))
+        assert tools == ["a", "b"]
+        assert session.calls == [None]
+
+    def test_follows_next_cursor_across_pages(self):
+        """A paginated server's tools are all collected across multiple calls."""
+        session = _FakeSession(
+            [
+                (None, _FakePage(["a", "b"], next_cursor="page2")),
+                ("page2", _FakePage(["c", "d"], next_cursor="page3")),
+                ("page3", _FakePage(["e"], next_cursor=None)),
+            ]
+        )
+        tools = asyncio.run(_list_all_tools(session))
+        assert tools == ["a", "b", "c", "d", "e"]
+        assert session.calls == [None, "page2", "page3"]
+
+    def test_empty_result(self):
+        session = _FakeSession([(None, _FakePage([], next_cursor=None))])
+        tools = asyncio.run(_list_all_tools(session))
+        assert tools == []