Agent document attachments are read from local paths

What changed

Agent sessions now send non-image attachments to the Agent as durable local file paths instead of automatically extracting PDF, Office (Word / Excel / PowerPoint), HTML, and text content into the prompt. Uploaded copies remain attached to the message until that message is deleted or edited to remove them.

The to_markdown document tool accepts those attachment paths in addition to workspace paths. Its authorization is unchanged in spirit: the session workspace, the agent data directory, and the files attached to the current session — every other local path is still rejected.

Why this matters to the user

Agents choose the appropriate tool or parser for each document and retain access to the original bytes across later turns. A response may differ from the previous eager text-extraction behavior when an Agent decides not to inspect an attached file.

What the user should do

Nothing — automatic. If a prompt requires the file to be inspected, state that explicitly.

Notes for release manager

Images keep their existing native-image/OCR routing. Files already inside the Agent workspace remain direct workspace-path references rather than copied snapshots.