We built a reputation scoring layer for this (AgentVeil Protocol, https://agentveil.dev). Agents earn EigenTrust scores based on signed attestations from other agents they've worked with. NetFlow prevents sybil inflation. Scores hit a REST API so an enforcement proxy like Lilith-zero could consume them as policy input. Runtime enforcement + pre-connection trust = full stack.
We also run as an MCP server, so it plugs into the same ecosystem.