Result Persistence and Rendering

Tool output is consumed by models, users, transcripts, evidence systems, artifact stores, and telemetry. These consumers need different representations.

Representations

Representation	Requirement
native_output	Preserve native protocol output or reference it.
model_facing_content	What the model receives. May be compacted, redacted, previewed, or reference-based.
structured_content	Machine-readable result conforming to output_schema when available.
ui_facing_rendering	UI projection hints; not canonical output.
transcript_search_text	Text intentionally indexed for transcript search.
persisted_payload_ref	Durable or session-scoped bytes for large outputs.
artifact_refs	Durable deliverables owned by Agent Artifact.
resource_refs	Fetchable resources owned by native protocols or resource systems.

Persistence decision

A tool_result_persistence SHOULD include decision_id, invocation_id, result_id, strategy, threshold, original_size_bytes, preview_size_bytes, persisted_ref, redaction_state, reason, and created_at.

Initial strategies:

• inline
• preview_and_persist
• ref_only
• redact
• drop_with_reason
• never_persist

Empty output

Tools can legitimately complete with no native output. A compatible runtime SHOULD emit an explicit empty-result marker or structured status so models and UIs do not confuse empty output with missing output.

Circular result guard

Some tools should opt out of persistence. A read-file tool, for example, may self-bound by ranges or token limits. Persisting its output into another file can create a read-persist-read loop.