A software development team is using an LLM-based tool to automatically refactor complex code. The tool operates in a loop: it analyzes a function, suggests an improvement, applies it, and then re-analyzes the newly modified function to find the next improvement. The team observes two recurring issues:

1. In one instance, the tool incorrectly renamed a variable in its first pass, which caused a cascade of errors in subsequent passes as it tried to 'fix' code that relied on the original variable name.
2. In another case, the tool ran for 20 cycles on a simple function, making minor, stylistic changes that did not improve performance or readability and significantly increased processing time.

Based on this scenario, identify and explain the two primary disadvantages of this looping, multi-step approach that the team is encountering.