Google explains eager vs. lazy loading of MCP tools in Agent Plugins

Google DevRel's James O'Reilly explains how Antigravity Agent Plugins expose local MCP server tools to the model, either eagerly as top-level functions or lazily through a call_mcp_tool proxy.

Eager loading, set via "eager": true in mcp_config.json, avoids the discovery turn but adds fixed per-turn token overhead that can degrade reasoning with 100+ tools.

Lazy loading is the plugin default and keeps baseline token use low, at the cost of an extra proxy hop and a higher chance of JSON quoting errors.