Constant MAX_BATCH_REFS 

pub const MAX_BATCH_REFS: usize = MCP_BATCH_MAX_SIZE; // 100usize

Slice 2 alias for MCP_BATCH_MAX_SIZE using the spec-language name (docs/MCP_TOOLS.md §1 / Slice 2 plan). The numeric value MUST equal MCP_BATCH_MAX_SIZE; an internal test pins the equivalence so the two constants cannot drift.