MCP Variance Log

Instructions

Implementation Reference

• src/mcp_variance_log/server.py:257-266 (handler)

  Handler implementation for the 'describe_table' tool. It extracts the table_name from arguments, queries sqlite_master for the table's CREATE SQL statement, and returns the result as text content.

  elif name == "describe_table":
      if not arguments or "table_name" not in arguments:
          raise ValueError("Missing table_name argument")
      table_name = arguments["table_name"]
      # Get table creation SQL instead of using PRAGMA
      results = db._execute_query(
          f"SELECT sql FROM sqlite_master WHERE type='table' AND name=?", 
          (table_name,)
      )
      return [types.TextContent(type="text", text=str(results))]

• src/mcp_variance_log/server.py:220-229 (schema)

  JSON schema defining the input for 'describe_table' tool: requires a 'table_name' string parameter.

  inputSchema={
      "type": "object",
      "properties": {
          "table_name": {
              "type": "string",
              "description": "Name of the table to describe"
          }
      },
      "required": ["table_name"]
  }

• src/mcp_variance_log/server.py:217-230 (registration)

  Registration of the 'describe_table' tool in the @server.list_tools() handler, specifying name, description, and input schema.

  types.Tool(
      name="describe_table",
      description="Show structure of a specific table",
      inputSchema={
          "type": "object",
          "properties": {
              "table_name": {
                  "type": "string",
                  "description": "Name of the table to describe"
              }
          },
          "required": ["table_name"]
      }
  ),