Analysis Reveals Claude Code Sends 62,600 Characters of Tool Definitions Per Turn

A comprehensive technical audit traced how Claude Code manages tool definitions and discovered it sends approximately 62,600 characters of tool definition data per turn. By comparing this against five different CLI-based implementations, the analysis reveals significant variation in how different tools allocate limited context window space.

For local LLM practitioners, this research has direct implications for agent design and model selection. Context windows are finite resources that determine how many tokens remain for actual reasoning and response generation. Understanding these overhead costs helps developers make informed choices: selecting models with adequate context windows, designing more efficient tool schemas, or adopting protocols like MCP that handle tool marshalling more elegantly. This empirical data transforms vague intuitions about "overhead" into concrete numbers that can guide architecture decisions.

Read the full article on r/LocalLLaMA.

Source: r/LocalLLaMA · Relevance: 8/10