The Problem
AI provides too much information when you needed a summary, cites irrelevant law when you specified a jurisdiction, or goes off on tangents. You waste time filtering out what you didn't need.
The Solution
Set explicit constraints on every dimension that matters:
- Length: "Max 300 words" / "No more than 5 bullet points"
- Jurisdiction: "England & Wales only" / "English law, not Scots law"
- Scope: "Commercial issues only, ignore tax"
- Depth: "High-level summary" vs "Detailed analysis"
- Audience: "For a non-lawyer client" vs "For counsel"
- Time: "Based on law as of 2025"
Before You Rely on This
The examples on this page are made up to show the technique. No test results have been published for it, so try it on your own work and judge it by what you find.
This guide is about how to word a prompt. It does not make a client's document or information safe to put into an AI tool. What you may enter depends on the plan your firm has, its agreement with the vendor and your firm's policy: Claude Projects for Client Matters sets out the checks for one tool. To practise, use a precedent or a published document that contains no client information, and refer to parties by role.
Why It Works
LLMs will expand to fill whatever space you give them. Without constraints, they default to "comprehensive" (i.e., long and unfocused). Explicit boundaries force prioritisation and relevance.
Example Constraints
Length Constraints
Summarise this case in exactly 3 bullet points.
Draft a clause on X. Max 150 words.
Provide a memo on this issue. 2 pages maximum, single-spaced.
Explain this concept in under 100 words.
Jurisdiction Constraints
Advise on employment law. England & Wales only - do not cite cases from
other jurisdictions.
This is an England & Wales matter. Scots law is not relevant.
Apply UK GDPR and the Data Protection Act 2018, not EU GDPR.
The contract is governed by English law. Do not apply any other law.
Scope Constraints
Focus only on data protection issues. Ignore contract law.
Commercial risks only - I'll handle tax separately.
Review for IP issues exclusively. Flag any IP-related clauses.
Employment law aspects only - ignore the corporate structure questions.
Depth Constraints
High-level overview for board presentation (not detailed analysis).
Detailed technical analysis - cite specific regulations and provisions.
Executive summary level - assume reader has no legal background.
Comprehensive review - miss nothing, even minor points.
Audience Constraints
Explain this for a non-lawyer CEO (avoid jargon).
Draft for the other side's solicitors (formal legal tone).
Write for a judge (authoritative but clear).
For a trainee solicitor (include teaching points).
Time Constraints
Based on law as of 1 January 2025 (ignore subsequent changes).
Current law only (2026) - older cases are not helpful.
What was the legal position in 2020? (not now)
Full Example
Without constraints:
Advise on whether we can dismiss this employee.
AI response: Several paragraphs covering every possible dismissal scenario across several jurisdictions, discussing both fair and unfair dismissal, redundancy, TUPE, and more. You have to hunt for the part you need.
With constraints:
Advise on whether we can dismiss this employee.
Constraints:
- England & Wales only
- Focus on dismissal for poor performance only
- Max 200 words
- Practical advice, not academic analysis
- Assume we have not yet started any process
AI response: A 200-word summary of the process for a performance dismissal in England and Wales, with next steps. Check it against authoritative sources before you use it.
Pro Tips
Stack multiple constraints:
[Task]
Constraints:
- Jurisdiction: England & Wales
- Length: Max 500 words
- Scope: Commercial issues only
- Audience: For non-lawyer board
- Depth: High-level implications, not detailed analysis
- Tone: Balanced (not alarmist)
Be specific about what to exclude:
Do not discuss tax implications.
Ignore procedural issues - focus on merits only.
No case law from outside England & Wales.
Combine with other guides:
- Output Format Control - specify both constraints AND format
- Role Assignment Precision - constraints + role = precise outputs
Common Mistakes
❌ Conflicting constraints: "Keep it under 100 words but be comprehensive." (Pick one)
❌ Too many constraints: a long list of requirements is hard to check the answer against
❌ Vague constraints: "Keep it short" (how short?), "Focus on key points" (which ones?)
✅ A few clear, specific, compatible constraints
Quick Reference
Template:
[Your task]
Constraints:
- Length: [specific word count or structure]
- Jurisdiction: [specific legal system]
- Scope: [what to include/exclude]
- Depth: [summary/detailed/comprehensive]
- Audience: [who will read this]
- [Any other relevant boundaries]
Before sending ANY prompt, ask yourself:
- How long should the response be?
- What jurisdiction applies?
- How deep should the analysis go?
- Who's the audience?
- What's out of scope?
Add those answers as constraints.