Add templates and tests

src/mcp_server_cli/templates/db_query.yaml

@@ -0,0 +1,21 @@
+name: db_query
+description: Execute read-only database queries
+
+input_schema:
+  type: object
+  properties:
+    query:
+      type: string
+      description: SQL query to execute
+      required: true
+    limit:
+      type: integer
+      description: Maximum number of rows to return
+      default: 100
+  required:
+    - query
+
+annotations:
+  read_only_hint: true
+  destructive_hint: false
+  non_confidential: false