What API usage limits document should you consult for detailed information?

The Salesforce App Limits Cheatsheet is the most appropriate document to consult for detailed information about API usage limits. This document provides a concise overview of various limits and considerations regarding API calls, including the specific limitations based on different Salesforce editions and service levels. It is designed to help developers and architects to easily reference the API call limits in Salesforce, allowing them to effectively plan and optimize their integration strategies.

The other documents, while valuable in their own rights, do not focus specifically on API usage limits. For example, the License Agreement Document outlines the terms and conditions related to the use of Salesforce products but does not provide API-related specifics. The Sierra API Reference is more geared toward the functionalities and specifications of the API itself rather than usage limits. The Web Service Best Practices Guide offers general best practices for designing and implementing web services but does not specifically address the limitations associated with API usage.