Field case 2026-07-11: workspace with mcp_tools=["blender"], agent showed blender 'initializing…' then dropped it. Root cause: blender-mcp connects to the Blender addon (host :9876) DURING init; addon wasn't running → Connection refused → agent gave up. Config was perfect (n8 mcp test PASS).
Fix: entry already knows BLENDER_HOST/BLENDER_PORT from the registry def env — TCP-probe declared dependency sockets at config-write time and print one line: '[nemesis8-entry] warning: blender addon not reachable at host.docker.internal:9876 — the blender tool will fail to initialize'. Generalize via an optional probe = "env:BLENDER_HOST:env:BLENDER_PORT" (or url) field on mcp-servers/*.toml rather than hardcoding blender.
Field case 2026-07-11: workspace with mcp_tools=["blender"], agent showed blender 'initializing…' then dropped it. Root cause: blender-mcp connects to the Blender addon (host :9876) DURING init; addon wasn't running → Connection refused → agent gave up. Config was perfect (n8 mcp test PASS).
Fix: entry already knows BLENDER_HOST/BLENDER_PORT from the registry def env — TCP-probe declared dependency sockets at config-write time and print one line: '[nemesis8-entry] warning: blender addon not reachable at host.docker.internal:9876 — the blender tool will fail to initialize'. Generalize via an optional
probe = "env:BLENDER_HOST:env:BLENDER_PORT"(or url) field on mcp-servers/*.toml rather than hardcoding blender.