Oracle MCP Server

Instructions

Implementation Reference

• src/oracle_mcp_server/server.py:781-798 (handler)

  Main handler logic for the 'describe_table' tool within the @self.server.call_tool() handler. Extracts table_name and owner arguments, invokes DatabaseInspector.get_table_columns(), formats the result as JSON, and returns it as TextContent.

  elif name == "describe_table":
      table_name = arguments.get("table_name")
      owner = arguments.get("owner")
  
      columns = await self.inspector.get_table_columns(table_name, owner)
  
      result = {
          "table_name": table_name,
          "owner": owner,
          "columns": columns,
          "column_count": len(columns),
      }
  
      return [
          TextContent(
              type="text", text=json.dumps(result, indent=2, default=str)
          )
      ]

• src/oracle_mcp_server/server.py:648-666 (schema)

  Input schema and metadata definition for the 'describe_table' tool, registered in the @self.server.list_tools() handler. Specifies required 'table_name' parameter and optional 'owner'.

  Tool(
      name="describe_table",
      description="Get detailed information about a table including columns, data types, and constraints",
      inputSchema={
          "type": "object",
          "properties": {
              "table_name": {
                  "type": "string",
                  "description": "Name of the table to describe",
              },
              "owner": {
                  "type": "string",
                  "description": "Schema owner (optional)",
                  "default": None,
              },
          },
          "required": ["table_name"],
      },
  ),

• src/oracle_mcp_server/server.py:218-280 (helper)

  Core implementation in DatabaseInspector.get_table_columns(): Executes SQL query against all_tab_columns and all_col_comments to fetch table column metadata (name, type, length, nullable, default, comments), applies COLUMN_WHITE_LIST filtering, and returns structured list of column dictionaries.

  async def get_table_columns(
      self, table_name: str, owner: Optional[str] = None
  ) -> List[Dict[str, Any]]:
      """Get detailed column information for a table"""
      conn = await self.connection_manager.get_connection()
      try:
          cursor = conn.cursor()
  
          query = """
              SELECT 
                  c.column_name,
                  c.data_type,
                  c.data_length,
                  c.data_precision,
                  c.data_scale,
                  c.nullable,
                  c.data_default,
                  cc.comments as column_comment,
                  c.column_id
              FROM all_tab_columns c
              LEFT JOIN all_col_comments cc ON c.owner = cc.owner 
                  AND c.table_name = cc.table_name 
                  AND c.column_name = cc.column_name
              WHERE c.table_name = :table_name
          """
  
          params = [table_name]
  
          if owner:
              query += " AND c.owner = :owner"
              params.append(owner)
  
          query += " ORDER BY c.column_id"
  
          cursor.execute(query, params)
  
          columns = []
          for row in cursor:
              # Apply column whitelist if configured
              full_column_name = f"{table_name}.{row[0]}"
              if COLUMN_WHITE_LIST and COLUMN_WHITE_LIST != [""]:
                  if full_column_name not in COLUMN_WHITE_LIST:
                      continue
  
              columns.append(
                  {
                      "column_name": row[0],
                      "data_type": row[1],
                      "data_length": row[2],
                      "data_precision": row[3],
                      "data_scale": row[4],
                      "nullable": row[5],
                      "data_default": row[6],
                      "column_comment": row[7],
                      "column_id": row[8],
                  }
              )
  
          return columns
  
      finally:
          conn.close()