SharePoint Best Practices
SharePoint Best Practices Library by SPDocKit
Monitoring and Logging
SharePoint Software Boundaries and Limits
SharePoint Software Boundaries and Limits Overview
Limits by Feature
Scope Rules Count per Search Service Application
Scope Rules Count per Search Scope
Search Topology Limits
Sharepoint Search Service Applications
User Profile Limits
Visio Services Limits
Word Automation Services
Limits by Hierarchy
Site Collection Health
Crawl Rules best practices report by SPDocKit determines whether the SharePoint 2010 Search Service application has been properly configured.
This check determines whether the SharePoint 2010 Search Service application has been properly configured.
The recommended limit is 100 crawl rules per application. Although this limit can be exceeded, the display of rules in Central Administration could be seriously degraded.
Make sure you do not go over the limit; if you do, reduce the number of rules to remain compliant.
Additional information can be found in the following article:
SharePoint Server 2010 capacity management: Software boundaries and limits