From the source
Droid's context engine now loads internal tool schemas, MCP tool schemas, skills, and plugin instructions only when a task needs them.
Factory's Deferred Context Engine reduces input context by keeping unused schemas and instructions out of the prompt until execution requires them.
Deferred context has been running in production.
Over the past five days, among measured Droid turns in sessions that triggered MCP tools, it cut estimated input tokens by 15.1% on average and reached a 39.4% p90 reduction .
Sessions with 100+ hidden deferred tools reached a 50.8% average reduction .
Droid still keeps the full context graph reachable: system instructions, repository rules, memories, internal tools, MCP tools, custom skills, plugins, subagents, prior messages, and live artifacts.
It starts with compact discovery metadata.
When a task needs a capability, Droid loads the relevant schema or instruction set; everything else stays out of the prompt.
The context bloat problem MCP expands Droid's execution surface.
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