The 'HTTP Suspicious Tool User Agent' detection rule by Raven Tait, designed for use with Splunk, analyzes web access logs to identify user agents that do not conform to standard browser behavior. By evaluating `nginx_access_logs`, the rule assesses the potential presence of security tools, scripting languages, and automation frameworks based on their user agent strings. Suspicious patterns may indicate malicious attempts to engage with web endpoints. The detection utilizes a lookup table to categorize known scripting tools, filtering based on activity that matches recognized malicious signatures. This anomaly detection can reveal unauthorized web interactions, aiding in identifying threat vectors associated with HTTP request smuggling or other web-based attacks.