diff --git a/src/jira_hub/commands.py b/src/jira_hub/commands.py
index 9ffd44f..baf1b6c 100644
--- a/src/jira_hub/commands.py
+++ b/src/jira_hub/commands.py
@@ -8,18 +8,31 @@ from . import mirror
 TEMP_KEY = re.compile(r"^new:\d+$")
 FIELD_PARAMS = ["summary", "description", "priority", "duedate", "planned_start", "planned_end", "epic_key", "assignee"]
 
+DATE = "YYYY-MM-DD"
+FIELD_HINTS = {"duedate": DATE, "planned_start": DATE, "planned_end": DATE, "epic_key": "ключ или new:<n>",
+               "assignee": "логин Jira"}
+
+# hints — формат значения для описания MCP batch_create, note — условие на набор параметров (#44)
 SPEC = {
     "ensure_issue": {"required": ["temp_key", "issue_type", "summary"],
                      "optional": ["description", "priority", "duedate", "planned_start", "planned_end", "labels",
                                   "epic_key", "assignee"],
-                     "keys": ["temp_key", "epic_key"]},
+                     "keys": ["temp_key", "epic_key"],
+                     "hints": {"temp_key": "new:<n>", "issue_type": "task|epic", "labels": "список", **FIELD_HINTS}},
     "ensure_fields": {"required": ["key"], "optional": FIELD_PARAMS + ["labels_add", "labels_remove"],
-                      "keys": ["key", "epic_key"]},
-    "ensure_comment": {"required": ["key", "marker", "body"], "optional": [], "keys": ["key"]},
-    "ensure_status": {"required": ["key", "target"], "optional": [], "keys": ["key"]},
-    "ensure_link": {"required": ["source", "target", "link_type"], "optional": ["replace"], "keys": ["source", "target"]},
-    "ensure_sprint": {"required": ["key", "sprint"], "optional": [], "keys": ["key"]},
-    "refresh": {"required": [], "optional": ["keys", "jql"], "keys": ["keys"]},
+                      "keys": ["key", "epic_key"],
+                      "hints": {**FIELD_HINTS, "labels_add": "список", "labels_remove": "список"},
+                      "note": "хотя бы одно поле"},
+    "ensure_comment": {"required": ["key", "marker", "body"], "optional": [], "keys": ["key"],
+                       "hints": {"marker": "метка в начале комментария"}},
+    "ensure_status": {"required": ["key", "target"], "optional": [], "keys": ["key"],
+                      "hints": {"target": "статус или список-путь"}},
+    "ensure_link": {"required": ["source", "target", "link_type"], "optional": ["replace"], "keys": ["source", "target"],
+                    "hints": {"link_type": "логическое имя из link_types", "replace": "true|false"}},
+    "ensure_sprint": {"required": ["key", "sprint"], "optional": [], "keys": ["key"],
+                      "hints": {"sprint": "имя спринта или backlog"}},
+    "refresh": {"required": [], "optional": ["keys", "jql"], "keys": ["keys"], "hints": {"keys": "список"},
+                "note": "keys или jql"},
 }
 WRITE_TYPES = [t for t in SPEC if t != "refresh"]
 LIST_PARAMS = {"labels", "labels_add", "labels_remove", "keys"}
@@ -69,6 +82,31 @@ def _is_str_list(value) -> bool:
     return isinstance(value, list) and all(isinstance(v, str) for v in value)
 
 
+def _names(spec, names) -> str:
+    return ", ".join(f"{n} ({spec['hints'][n]})" if n in spec.get("hints", {}) else n for n in names)
+
+
+def describe() -> str:
+    """Параметры всех типов команд, строка на тип (необязательные — в [ ]): описание MCP batch_create из SPEC (#44)."""
+    lines = []
+    for ctype, spec in SPEC.items():
+        line = f"- {ctype}: {_names(spec, spec['required']) or '—'}"
+        if spec["optional"]:
+            line += f"; [{_names(spec, spec['optional'])}]"
+        if spec.get("note"):
+            line += f" — {spec['note']}"
+        lines.append(line)
+    return "\n".join(lines)
+
+
+def _expected(spec) -> str:
+    """Хвост ошибки «нет …» / «лишние параметры …»: какие параметры тип ожидает (#44)."""
+    parts = [f"ожидаются {', '.join(spec['required'])}"] if spec["required"] else []
+    if spec["optional"]:
+        parts.append(f"необязательные {', '.join(spec['optional'])}")
+    return "; ".join(parts)
+
+
 def validate(commands) -> list[dict]:
     if not isinstance(commands, list) or not commands:
         raise CommandError("пакет без команд")
@@ -84,10 +122,11 @@ def validate(commands) -> list[dict]:
         spec = SPEC[ctype]
         missing = [f for f in spec["required"] if params.get(f) in (None, "", [])]
         if missing:
-            raise CommandError(f"команда {i} ({ctype}): нет {', '.join(missing)}")
+            raise CommandError(f"команда {i} ({ctype}): нет {', '.join(missing)}; {_expected(spec)}")
         unknown = set(params) - set(spec["required"]) - set(spec["optional"])
         if unknown:
-            raise CommandError(f"команда {i} ({ctype}): лишние параметры {', '.join(sorted(unknown))}")
+            raise CommandError(f"команда {i} ({ctype}): лишние параметры {', '.join(sorted(unknown))}; "
+                               f"{_expected(spec)}")
         bad = [e for e in (_type_error(ctype, n, v) for n, v in params.items()) if e]
         if bad:
             raise CommandError(f"команда {i} ({ctype}): " + "; ".join(bad))
diff --git a/src/jira_hub/mcp_server.py b/src/jira_hub/mcp_server.py
index 2fdcbd8..548a788 100644
--- a/src/jira_hub/mcp_server.py
+++ b/src/jira_hub/mcp_server.py
@@ -9,6 +9,7 @@ import time
 from mcp.server.fastmcp import FastMCP
 
 from .client import HubClient, HubError, HubUnavailable
+from .commands import describe
 
 OFFLINE = "хаб не запущен: jira-hub serve"
 POLL_SECONDS = 5
@@ -159,13 +160,22 @@ def notes_set(key: str, fact_status: str | None = None, work_kind: str | None =
     return "заметки " + key + ": " + "; ".join(f"{k}: {note.get(k)}" for k in ("fact_status", "work_kind", "done_text", "rest_text", "owner_note") if note.get(k))
 
 
+def _doc(text: str):
+    """Описание инструмента, собранное в коде: FastMCP берёт его из __doc__ при регистрации."""
+    def deco(fn):
+        fn.__doc__ = text
+        return fn
+    return deco
+
+
 @mcp.tool()
 @guard
+@_doc("""Поставить пакет команд. Каждая команда — {"type": <тип>, "params": {...}}. Хвостовой refresh хаб добавит сам.
+Параметры по типам (необязательные — в [ ]):
+""" + describe() + """
+ensure_issue передавайте с labels, включающими базовую метку проекта (AWPCA): хаб и агент метки сами не добавляют,
+задача без неё выпадет из базовой JQL и из зеркала.""")
 def batch_create(title: str, commands: list[dict]) -> str:
-    """Поставить пакет команд. Каждая команда — {"type": ensure_issue|ensure_fields|ensure_comment|ensure_status|
-    ensure_link|ensure_sprint|refresh, "params": {...}} по контракту specs/commands. Хвостовой refresh хаб добавит сам.
-    ensure_issue передавайте с labels, включающими базовую метку проекта (AWPCA): хаб и агент метки сами не добавляют,
-    задача без неё выпадет из базовой JQL и из зеркала."""
     b = _client().post("/batches", {"title": title, "author": AUTHOR, "commands": commands})
     return f"пакет #{b['id']} поставлен: {b['count']} команд, оценка ≈ {round(b['estimate_seconds'] / 60)} мин"
 
diff --git a/tests/test_commands.py b/tests/test_commands.py
index 62e15ef..45f0783 100644
--- a/tests/test_commands.py
+++ b/tests/test_commands.py
@@ -37,6 +37,29 @@ def test_validate_errors(bad, msg):
         commands.validate(bad)
 
 
+def test_missing_param_error_names_expected():
+    """Клиент со старым описанием исправляет пакет с одной попытки (#44): ensure_status {key, status}."""
+    with pytest.raises(CommandError) as e:
+        commands.validate([{"type": "ensure_status", "params": {"key": "A-1", "status": "Готово"}}])
+    assert str(e.value) == "команда 1 (ensure_status): нет target; ожидаются key, target"
+
+
+def test_unknown_param_error_names_expected():
+    with pytest.raises(CommandError) as e:
+        commands.validate([{"type": "ensure_sprint", "params": {"key": "A-1", "sprint": "Спринт 2", "board": "1"}}])
+    assert str(e.value) == "команда 1 (ensure_sprint): лишние параметры board; ожидаются key, sprint"
+    with pytest.raises(CommandError) as e:
+        commands.validate([{"type": "ensure_link", "params": {"source": "A-1", "target": "A-2", "link_type": "связанные",
+                                                              "force": True}}])
+    assert str(e.value) == ("команда 1 (ensure_link): лишние параметры force; "
+                            "ожидаются source, target, link_type; необязательные replace")
+
+
+def test_spec_hints_name_known_params():
+    for ctype, spec in commands.SPEC.items():
+        assert set(spec.get("hints", {})) <= set(spec["required"]) | set(spec["optional"]), ctype
+
+
 def test_substitute_and_estimate():
     p = commands.substitute("ensure_link", {"source": "new:60", "target": "A-1", "link_type": "связанные"}, {"new:60": "A-9"})
     assert p["source"] == "A-9"
diff --git a/tests/test_mcp.py b/tests/test_mcp.py
index 429929e..f365f4b 100644
--- a/tests/test_mcp.py
+++ b/tests/test_mcp.py
@@ -6,7 +6,7 @@ from types import SimpleNamespace
 
 import pytest
 
-from jira_hub import api, mcp_server, settings
+from jira_hub import api, commands, mcp_server, settings
 from jira_hub.client import HubClient
 
 
@@ -204,6 +204,23 @@ def test_batch_create_mentions_labels():
     assert "labels" in doc and "AWPCA" in doc
 
 
+def test_batch_create_description_lists_params_from_spec():
+    """Клиент MCP не видит specs/commands: описание инструмента перечисляет параметры каждого типа из SPEC (#44)."""
+    tools = {t.name: t for t in asyncio.run(mcp_server.mcp.list_tools())}
+    desc = tools["batch_create"].description
+    for ctype, spec in commands.SPEC.items():
+        line = next(ln for ln in desc.splitlines() if ln.startswith(f"- {ctype}:"))
+        required, _, optional = line.removeprefix(f"- {ctype}:").partition("; [")
+        for name in spec["required"]:
+            assert re.search(rf"\b{name}\b", required), (ctype, name)
+        for name in spec["optional"]:
+            assert re.search(rf"\b{name}\b", optional), (ctype, name)
+        for name, hint in spec.get("hints", {}).items():
+            assert f"{name} ({hint})" in line, (ctype, name)
+    assert "target (статус или список-путь)" in desc and "sprint (имя спринта или backlog)" in desc
+    assert "labels" in desc and "AWPCA" in desc
+
+
 def test_fmt_agent_update_lines():
     base = {"online": True, "agent_version": "6", "current_command_id": None, "rate_limited_24h": 0, "redelivered": [],
             "warning": None, "last_seen_at": "2026-10-14T20:00:00+00:00", "settings_version": 3}