fix: report unknown services by what the server can see

server/tools/_services.py

@@ -0,0 +1,22 @@
+from __future__ import annotations
+
+from server.state import get_service_registry
+from server.store.service_registry import load_effective_services
+
+
+async def unknown_service_message(service: str) -> str:
+    """Explain an unknown-service lookup in terms of what the server can actually see.
+
+    The effective service list merges config.yaml with dynamically-registered
+    services, so a miss has two very different causes: a genuine typo, or a server
+    that loaded no config at all (e.g. config.yaml not mounted into the container).
+    Listing the known names tells those apart instead of guessing at config.yaml.
+    """
+    services = await load_effective_services(get_service_registry())
+    if not services:
+        return (
+            f"Service `{service}` not found — this server has no services at all "
+            f"(config.yaml is empty or was never loaded, and nothing is registered)."
+        )
+    known = ", ".join(f"`{s.name}`" for s in sorted(services, key=lambda s: s.name))
+    return f"Service `{service}` not found. Known services: {known}."

server/tools/history.py

@@ -5,6 +5,7 @@
 from server.embeddings import get_embedding_provider
 from server.indexer.git_history import GitHistoryPipeline
 from server.state import get_commit_store
+from server.tools._services import unknown_service_message
 
 
 def register_history_tools(mcp: MCPServer) -> None:
@@ -126,7 +127,7 @@ async def index_history(
         if service:
             result = await pipeline.index_service(service, force=force)
             if "error" in result:
-                return f"Service `{service}` not found in config.yaml."
+                return await unknown_service_message(service)
             lines = [
                 f"Git history indexed for `{service}`:",
                 f"- New commits: {result['new']}",

server/tools/index.py

@@ -4,6 +4,7 @@
 
 from server.indexer.pipeline import IndexPipeline
 from server.state import get_store
+from server.tools._services import unknown_service_message
 
 
 def register_index_tools(mcp: MCPServer) -> None:
@@ -25,7 +26,7 @@ async def reindex(
         if service:
             result = await pipeline.index_service(service, force=force)
             if "error" in result:
-                return f"Service `{service}` not found in config.yaml."
+                return await unknown_service_message(service)
             return (
                 f"Reindex complete for `{service}`:\n"
                 f"- Files indexed: {result['files']}\n"

tests/tools/test_history.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from types import SimpleNamespace
 from unittest.mock import AsyncMock, patch
 
 from server.tools.history import register_history_tools
@@ -111,18 +112,23 @@ async def test_get_commit_formats_changed_files_and_truncation() -> None:
     assert "Diff truncated" in result
 
 
-async def test_index_history_reports_unknown_service() -> None:
+async def test_index_history_unknown_service_lists_known_services() -> None:
     index_history = _tool("index_history")
     pipeline = AsyncMock()
     pipeline.index_service.return_value = {"error": 1}
 
     with (
         patch("server.tools.history.get_commit_store", return_value=AsyncMock()),
         patch("server.tools.history.GitHistoryPipeline", return_value=pipeline),
+        patch("server.tools._services.get_service_registry"),
+        patch(
+            "server.tools._services.load_effective_services",
+            AsyncMock(return_value=[SimpleNamespace(name="orders")]),
+        ),
     ):
         result = await index_history(service="unknown")
 
-    assert result == "Service `unknown` not found in config.yaml."
+    assert result == "Service `unknown` not found. Known services: `orders`."
 
 
 async def test_index_history_single_service_reports_diff_updates() -> None:

tests/tools/test_index.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from types import SimpleNamespace
 from unittest.mock import AsyncMock, patch
 
 from server.tools.index import register_index_tools
@@ -10,18 +11,48 @@ def _tool(name: str):
     return get_tool(register_index_tools, name)
 
 
-async def test_reindex_reports_unknown_service() -> None:
+async def test_reindex_unknown_service_lists_known_services() -> None:
     reindex = _tool("reindex")
     pipeline = AsyncMock()
     pipeline.index_service.return_value = {"error": 1, "files": 0, "chunks": 0}
 
     with (
         patch("server.tools.index.get_store", return_value=AsyncMock()),
         patch("server.tools.index.IndexPipeline", return_value=pipeline),
+        patch("server.tools._services.get_service_registry"),
+        patch(
+            "server.tools._services.load_effective_services",
+            AsyncMock(
+                return_value=[
+                    SimpleNamespace(name="orders"),
+                    SimpleNamespace(name="catalog"),
+                ]
+            ),
+        ),
     ):
         result = await reindex(service="unknown")
 
-    assert result == "Service `unknown` not found in config.yaml."
+    assert result == "Service `unknown` not found. Known services: `catalog`, `orders`."
+
+
+async def test_reindex_unknown_service_flags_empty_service_list() -> None:
+    reindex = _tool("reindex")
+    pipeline = AsyncMock()
+    pipeline.index_service.return_value = {"error": 1, "files": 0, "chunks": 0}
+
+    with (
+        patch("server.tools.index.get_store", return_value=AsyncMock()),
+        patch("server.tools.index.IndexPipeline", return_value=pipeline),
+        patch("server.tools._services.get_service_registry"),
+        patch(
+            "server.tools._services.load_effective_services",
+            AsyncMock(return_value=[]),
+        ),
+    ):
+        result = await reindex(service="auth-server")
+
+    assert "has no services at all" in result
+    assert "never loaded" in result
 
 
 async def test_reindex_single_service_reports_counts() -> None: