Early finding: Claude Code picks Custom/DIY in 12 of 20 categories. Not because it can't use the tools (BFCL scores suggest it can) but because it doesn't reach for them. That's a different failure mode than capability benchmarks measure.

We score each tool on: agent visibility, pick rate vs Custom/DIY, cross-context breadth, expert human ratings, and implementation success rate. Tools above survival=1 persist. Below it, agents synthesize around them.

Methodology is at survivalindex.org/methodology. Very curious what people think of the measurement approach, especially the human coefficient variable.