body: [What is a contract and what is required for them to be valid?](https://law.stackexchange.com/questions/6263/what-is-a-contract-and-what-is-required-for-them-to-be-valid/6264#6264) explains the basics of a contract. However, any simple contract may potentially have ambiguities that would make it difficult or impossible to decide if the contract is being fulfilled. For example, if I make a contract for someone to fix my car, I should actually specify what exactly needs fixing and what would constitute being fixed. Otherwise the person could just top off the oil and call it a day.
  
  
  Presumably at some point, common sense is exercised to decide if some unexpected development follows this spirit and intent of the contract or not. After all, it's difficult if not impossible to state anything with perfect disambiguity. But [some contract authors still try](https://en.wikipedia.org/wiki/End-user_license_agreement#Criticism). Since EULAs are probably written by some pretty good lawyers, does that mean that such overly detailed documents can be considered the standard of a very good contract? What *is* a reasonable standard for how much a contract should specify, and how much should be left to "well, let's just hope we can all come to some agreement if and when that weird freak case happens".
  
  
  When contract lawyers write a contract, how do they decide when it's "detailed enough"? Are there rules of thumb that a lay person could use?
  
  
  
title: How to judge if a contract is detailed enough?