Artifact and docs reads can now be marked with markReads

What

Artifacts are documents, apps and data Claude can create and read through the artifact tool. A new markReads setting on a stored artifact or doc changes how its reads are reported:

• The artifact tool actions read, list_files, read_file, list_assets, read_asset, read_db, comments, verify, get_endpoints, call_endpoint and run_script now record their output and the id of the call as marked reads when the artifact's stored record has markReads set.
• When an output is marked, the result Claude sees starts with a marker text. What the text says, and what sets markReads, were not traced.
• A docs read result now returns markReads: true when the flag is set, instead of authoredByOthers.
• An artifact database read does the same: markReads when the flag is set, otherwise authoredByOthers as before.

Why

Content read from some artifacts and docs is now labelled in what Claude sees, in place of the earlier authoredByOthers marking for those cases. What the label is used for is not shown.