Legal

Review contracts with a strong model and redline with a cheaper subagent

A law firm reviews contracts with Claude Opus and hands Word redlining to a Sonnet subagent, cutting the cost of the document work about 5x.

By A Reddit user on Reddit · Posted · Added Oct 16, 2026

Difficulty
AdvancedOur rating
Time to build
Not reportedOur estimate
Monthly cost
Not reported
Revenue
Not reportedWe only show revenue the source states
Result
Sourced: ~5x cheaper document handling
Engagement
No public countThe source shows no number

What they did

The firm used Claude Cowork to review, redline and comment on .docx files with Opus at max effort, which was expensive. It now keeps Opus for legal review and routes all DOCX operations through a Sonnet subagent with a DOCX skill and MCP.

How it went

They report the docx interaction cost dropped about 5x.

Worth knowing

Keep the legal judgment on the strongest model and a lawyer in the loop.

Builder recipe

Our own starting point, written from the source. Adapt it to your setup.

Stack

  • Claude (Opus for review, Sonnet subagent for DOCX)
  • A DOCX MCP or skill

Steps

  1. Collect the documents.
  2. Have the agent extract and summarize.
  3. Have a qualified person review.
  4. Store the result securely.

Starter prompt

Review this contract against our playbook and list issues with clause references. Then ask the DOCX subagent to apply tracked changes and comments for each.

Tags

Agent Claude
Role Lawyer
Industry Legal

Read the original

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