Ecosystem Boundaries

Agent Tool should stay narrow.

Adjacent layer	Boundary
Runtime	Runtime executes and schedules. Tool records the callable capability and call facts.
Policy	Policy decides. Tool describes risk and required permissions.
Evidence	Evidence verifies and audits. Tool links invocation and result facts.
Artifact	Artifact owns durable deliverables. Tool links results to artifacts.
UI	UI renders and controls. Tool provides machine-readable state.
Knowledge	Knowledge provides source-grounded context. Tool may retrieve or cite it but does not own it.
Skills	Skills package instructions and workflows. Tool exposes executable capabilities.
MCP/OpenAPI/provider APIs	Native protocols own wire semantics. Tool preserves mappings and adds agent-specific lifecycle.