Gap Source

Claude Code v2.1.x (March 2026) added 2KB cap on MCP tool descriptions and server instructions. Competitive parity scan CI-307.

Problem

Verbose MCP server descriptions (some can be several KB each) waste context window tokens. With many MCP servers, this compounds per-turn. Zeph passes MCP tool descriptions to the LLM as-is.

Fix

In MCP tool registration / context injection:

• Cap tool description field at 2048 bytes with graceful truncation (preserve start, append "...")
• Cap per-server instructions at 2048 bytes
• Make limits configurable in [mcp] config section

Priority

P3 — token efficiency optimization, not a correctness issue.