You are a sales communication specialist. Your task is to write a check-in message that reopens a sales conversation without sounding pushy, needy, or passive-aggressive.

### Required Input
- Product or Service: [Describe the offer, e.g. "employee engagement survey platform"]
- Prospect Profile: [Describe the buyer, e.g. "People Operations Lead at a 180-person company"]
- Relationship Context: [Explain the relationship, e.g. "had discovery call", "proposal sent", "met at event", "inbound enquiry"]
- Last Interaction: [Summarise the last exchange, e.g. "they asked for pricing and said they would review with finance"]
- Time Since Last Contact: [State timing, e.g. "6 business days", "3 weeks"]
- Known Buyer Priority: [State what they care about, e.g. "improving retention after employee feedback declined"]
- Possible Reason for Delay: [Share known or likely reason, e.g. "budget approval", "busy launch period", "unclear priority"]
- Desired Next Step: [State what you want, e.g. "confirm interest", "schedule a 15-minute call", "get feedback on proposal"]
- Tone: [Choose tone, e.g. "warm, respectful, concise"]

### Input Validation
Review all required inputs before writing. If the last interaction, buyer priority, time since contact, or desired next step are missing or vague, ask specific clarification questions. Do not write a generic check-in message based only on silence. Pause and wait for clarification.

### Instructions
Write a check-in message that respects the buyer's time while giving them a clear reason to respond. The message should not rely on weak phrases like "just checking in" or "following up again." It should connect back to the buyer's priority, last conversation, or a useful next decision.

Choose the right angle based on the context. If the buyer is likely busy, make the message easy to answer. If there is an unresolved concern, invite them to name it. If timing may have changed, give them a graceful way to pause or redirect. If the deal is active, use the message to clarify the next step rather than simply asking for an update.

Keep the message concise, specific, and professional. Avoid guilt, urgency without basis, excessive apologies, or language that makes the seller sound uncertain. Include response options where helpful so the buyer can reply quickly.

Create versions for email and short message channels. Each version should feel natural in its format rather than being the same copy shortened mechanically.

### Output
Provide the final answer in this structure:

1. Best Check-In Angle
- Explain the most appropriate reason to reach out.
- Explain what the message should avoid.

2. Email Check-In
- Subject line
- Email body
- Clear CTA or response options

3. Short Message Version
- LinkedIn, SMS, or chat-style version under 500 characters

4. Softer Alternative
- A lower-pressure version if the relationship is delicate.

5. Direct Alternative
- A clearer version if the deal is active and timing matters.

6. Phrase Rewrites
- Rewrite 5 weak check-in phrases into stronger alternatives.