list_tables

Instructions

Implementation Reference

• server.py:160-222 (handler)

  The 'list_tables' tool handler function. It takes a database_id parameter, fetches table metadata from Metabase via GET /api/database/{database_id}/metadata, extracts table info (id, display_name, description, entity_type), sorts by display_name, and returns formatted markdown output.

  async def list_tables(database_id: int, ctx: Context) -> str:
      """
      List all tables in a specific database.
  
      Args:
          database_id: The ID of the database to query.
  
      Returns:
          Formatted markdown table showing table details.
      """
      try:
          await ctx.info(f"Fetching tables for database {database_id}")
          result = await metabase_client.request("GET", f"/database/{database_id}/metadata")
  
          # Extract and format tables
          tables = result.get("tables", [])
          await ctx.debug(f"Found {len(tables)} tables in database {database_id}")
  
          formatted_tables = [
              {
                  "table_id": table.get("id"),
                  "display_name": table.get("display_name"),
                  "description": table.get("description") or "No description",
                  "entity_type": table.get("entity_type")
              }
              for table in tables
          ]
  
          # Sort for better readability
          formatted_tables.sort(key=lambda x: x.get("display_name", ""))
  
          # Generate markdown output
          markdown_output = f"# Tables in Database {database_id}\n\n"
          markdown_output += f"**Total Tables:** {len(formatted_tables)}\n\n"
  
          if not formatted_tables:
              await ctx.warning(f"No tables found in database {database_id}")
              markdown_output += "*No tables found in this database.*\n"
              return markdown_output
  
          # Create markdown table
          markdown_output += "| Table ID | Display Name | Description | Entity Type |\n"
          markdown_output += "|----------|--------------|-------------|--------------|\n"
  
          for table in formatted_tables:
              table_id = table.get("table_id", "N/A")
              display_name = table.get("display_name", "N/A")
              description = table.get("description", "No description")
              entity_type = table.get("entity_type", "N/A")
  
              # Escape pipe characters
              description = description.replace("|", "\\|")
              display_name = display_name.replace("|", "\\|")
  
              markdown_output += f"| {table_id} | {display_name} | {description} | {entity_type} |\n"
  
          await ctx.info(f"Successfully formatted {len(formatted_tables)} tables")
          return markdown_output
  
      except Exception as e:
          error_msg = f"Error listing tables for database {database_id}: {e}"
          await ctx.error(error_msg)
          raise ToolError(error_msg) from e

• server.py:159-159 (registration)

  The '@mcp.tool' decorator that registers the 'list_tables' function as an MCP tool with the FastMCP server instance.

  @mcp.tool

• server.py:160-160 (schema)

  The function signature defines the input schema: 'database_id: int' is the required parameter, and 'ctx: Context' is the MCP context. The return type is 'str' (formatted markdown).

  async def list_tables(database_id: int, ctx: Context) -> str: