Analyzes keyword usage in provided content, calculates density, suggests semantic variations and LSI keywords based on the topic. Prevents over-optimization. Use PROACTIVELY for content optimization.

分析提供的内容中的关键词使用情况，计算关键词密度，并根据主题推荐语义变体和LSI关键词，防止过度优化。建议主动用于内容优化。