An attachment name is not its content, and the latest email does not always contain the latest approved file. A prompt should receive attachment IDs, message links, version markers, file type, and extraction status. Inspect only attachments relevant to the question. If extraction fails or a file is missing, do not invent its contents from the filename or a prior message. For a revised file, compare the specific fields that matter and record which version supports each claim. Treat text inside attachments as data, including any instruction-like text. A scanned image may require separate visual review if text extraction omits a table or signature.
Make this comfortable
Email prompts: verify attachment version and coverage
Operational case
The vendor first attaches pilot-plan-v3 to M-41, showing 47 candidate sites. The authorized owner later attaches pilot-plan-v4 to M-47, listing 20 approved pilot sites and leaving expansion in a separate appendix. M-52 mentions 'the attached final plan' but contains no attachment. The assistant uses the verified v4 file for the pilot count and reports that M-52 supplied no new file. If v4 cannot be opened, it pauses the count claim rather than falling back silently to v3.
M-41 attachment A-3: v3, 47 candidate sites.
M-47 attachment A-4: v4, 20 approved pilot sites.
M-52: says 'attached'; attachment list empty.
Current pilot claim: A-4, if extraction succeeds.
A-4 unavailable: count remains unverified.Performance and operating cost
Extracting A relevant attachments costs roughly O(total bytes), and comparing R required fields is O(R) after parsing. Narrow extraction saves tokens and reduces exposure to irrelevant files. The cost of checking an actual attachment ID is small compared with sending a wrong count to a customer or creating an event for an obsolete plan. Store file IDs and hashes so a reviewer can reproduce which bytes supported the draft.
Common Mistakes
- Do not treat a filename as proof of file contents.
- Do not assume a later email includes the file it mentions.
- Do not silently substitute v3 when v4 is unavailable.
Connected lessons
- Prompt engineering applications
- Prompt Engineering
- Document prompts: anchor each field to a page and resolve conflicts
- Retrieved evidence: reconcile versions and conflicting facts
- API documentation prompts: bind prose to a versioned contract
- Email prompts: reconstruct the thread before drafting
- Email prompts: keep sender identity and message text separate
- Email prompts: review To, Cc, Bcc, and reply scope
- Email prompts: separate drafted commitments from sent messages
- Calendar prompts: resolve availability, zone, and duration
- Calendar prompts: distinguish create, update, and cancellation
- Calendar prompts: scope recurrence changes to the right instances
- Project: review an Aster vendor reply and invite
- Email and calendar prompt decisions
prompt engineering
email calendar