Show HN: `npx subagent-reuse --setup` adds an MCP that scans ~/.claude/projects/, builds SHA-256 Merkle trees of files each subagent already read/modified, and route_task decides REUSE vs CREATE_NEW before spawn—structural overlap only, no embeddings; ~1k LOC JS + 52 tests.
Local-first Apache-2.0 CLI for Claude Code/Codex/Cursor: mcp-xray ranks bloated tool schemas, sync compresses CLAUDE.md↔AGENTS.md↔Cursor rules, and shield fails CI on leaked keys/prompt-injection/Trojan Unicode—claims large cuts in model-visible prompt size without API calls.
Empirical study: 34% of popular active repos ship agent instruction files (AGENTS.md dominant); half exceed ~100 lines; ~3/5 rules could be script-checked but <1/20 name the check—actionable lint: short map, name enforcers, one rulebook.