Add evidence intentionally#
Use an attachment when it supplies information the request needs. Explain what the agent should inspect and the action you want. “Compare this screenshot with the expected layout” is clearer than an unexplained image.
Check that the attachment is the correct version and contains no unnecessary private material. Remove accidental files before sending. If a screenshot’s thumbnail looks cropped, inspect the source image or open the received attachment before concluding that content was lost.
Confirm delivery separately#
A preview in CueSpec means the file is selected, not that Codex received it. After sending, verify the intended conversation and attachment if the outcome matters. An uncertain send should preserve the draft and avoid blind duplication.
The development history includes a real-user confirmation for screenshot color handling. It does not establish every file type, size or complex attachment combination. No reviewed general upload-size limit is supplied here. For failures, report the smallest reproducible file and the visible stage, with sensitive contents removed.