Assistants in BlackMountain are designed for recurring tasks. To make them effective, you define their behavior through custom instructions and provide context through file attachments. This article explains how to write high-quality instructions and attach the right files.
Why Instructions Matter
Instructions are the core of your assistant. They define role, task, output format, and constraints. Well-written instructions lead to consistent, high-quality output. Poorly written instructions produce generic or unpredictable results.
How to Write Effective Instructions
The Core Framework: 5 Essential Sections
Every solid system prompt includes these five building blocks:
Section | What to include | Common mistake |
Role | Who the assistant is. Tone, perspective, expertise level. Max 2-3 sentences. | Too many superlatives ("the world's best expert") → creates bias |
Context | What input does the assistant receive? Who is it working for? What constraints apply? | Often forgotten → assistant guesses instead |
Task | What exactly should it do? For complex workflows: break into steps. | Too vague ("Help the user") instead of specific ("Create a summary in 3 bullet points") |
Output Format | Exact structure: length, labels, markdown format, JSON, table, etc. | Missing completely → inconsistent output every time |
Rules | Style rules, forbidden words, language, guardrails | Contradictions between Role and Rules |
Pro tip: Write specific, not vague. Instead of "Be friendly," write "Use a professional, conversational tone without emojis."
Optional Sections (When Needed)
Evaluation Criteria — When the assistant evaluates, ranks, or analyzes something
Examples — When the output format is complex or unusual (use
<example>tags)Negative Examples — When specific mistakes keep happening (use
<negative_example>tags)
Example: DACH Brand Voice Editor Instructions
Here's a complete example of well-structured instructions:
You are a brand voice editor for the DACH region. Your task is to review and refine marketing copy to ensure it matches our brand guidelines. ## RoleProfessional brand voice editor with expertise in DACH markets (Germany, Austria, Switzerland). ## Task- Review marketing copy for tone, style, and consistency- Refine messaging to match brand guidelines- Ensure cultural appropriateness for DACH audiences ## Output FormatAlways provide:1. Original text analysis2. Revised version3. Key changes explained ## Rules- Never change product names or technical terms- Maintain professional yet approachable tone- Always reference brand guidelines from attached files
File Attachments: Providing Context
Why Attach Files?
File attachments give your assistant access to specific knowledge: brand guidelines, reference documents, style guides, templates, or technical specifications. Attached files are available in every conversation with this assistant.
How to Attach Files
Once the Assistant is created, click on it in the Assistant Studio.
Scroll to the File Attachments section (below Instructions)
Click Upload File or drag-and-drop a file
Supported formats: PDF, DOCX, TXT, MD, CSV (verify platform limits)
Attach up to [X] files per assistant (verify limit with user)
What to Attach
Brand guidelines — Tone, style, terminology
Reference documentation — Product specs, FAQs, process documentation
Templates — Email templates, report structures
Style guides — Writing conventions, formatting rules
File size limit: Check the maximum file size per upload and total attachments per assistant. Large files may slow down assistant response time.
Best Practices for Instructions
Show, Don't Tell
Instead of writing "Write concisely," show an example that IS concise.
Separate Concerns
Format rules (how does it look?) → Output Format section
Style rules (how does it sound?) → Rules section
Decision logic (how does it decide?) → Evaluation Criteria section
Build in Anti-Bias
If the role implies a perspective (e.g., "Marketing Expert"), add explicitly:
"Evaluate neutrally based on defined criteria, not based on personal preference."
Be Specific, Not Vague
❌ Vague | ✅ Specific |
"Write a summary" | "Write a summary with exactly 3 bullet points, max 20 words per point" |
"Be friendly" | "Use a professional, conversational tone without emojis" |
"Answer in German" | "All outputs in German. Technical terms may remain in English if no common German equivalent exists." |
Saving & Testing Your Assistant
Once you've configured your assistant, click Create (or Save if editing an existing assistant).
Test in Chat
Navigate to Chat
Select your assistant from the Assistant dropdown
Test with example inputs to verify behavior
Refine instructions if output doesn't match expectations
Best practice: Test your assistant with edge cases and unexpected inputs before sharing it with your team. Adjust instructions based on real-world usage.
Next Steps
Now that you know how to write custom instructions and attach files:
Create your first assistant for a recurring task
Share it with your team to scale consistent output
Need help? Visit our FAQs & Troubleshooting or contact support.