Designing an Agent: Role, Inputs, Tools, Limits

Before building, write a one-page design. It forces the decisions an agent will otherwise make badly for you.

The people, companies and numbers in this lesson are made up. Check any figure against your own situation before you rely on it.

The Eight Parts

• Role: who is this agent, and what is it responsible for?
• Goal: what result counts as done, in one sentence?
• Inputs: what will it be given, and in what form?
• Tools: which systems may it read and which may it change?
• Skills: which of your methods should it load?
• Limits: the hard rules from Permissions, Secrets and What an Agent Should Never Do.
• Review points: where does a person look before anything leaves the building?
• Output: the exact format of the result.

A Filled Design Page (Maya's Prospect Research Agent, Made-Up)

• Role: researches one company at a time before Maya's discovery calls.
• Goal: a one-page briefing with every claim sourced, ready 30 minutes before the call.
• Inputs: a company name and website, the call date, Maya's notes from earlier contact.
• Tools: web search and page reading, read only. No email, no CRM write.
• Skills: the briefing skill (see the sales track), the claim ledger format.
• Limits: public sources only, at most 15 pages read, stop and report if the company can't be identified, no personal social media about individuals.
• Review points: Maya reads the briefing and checks three claims against sources before the call.
• Output: summary of 120 words, a table of claims with links, a list of unknowns.

Keep the Role Narrow

An agent that does one job well beats a general assistant that does ten jobs poorly. If your design page runs past a page, you probably have two agents. Split by job, not by tool.

The Stop Test

Read the design aloud and finish this sentence for each part: 'If this is missing, the agent will guess ___.' Anything you can't fill in is a decision you haven't made yet.

Common Mistakes

• Giving the agent every tool 'just in case'. Fix: list only the tools the goal needs.
• No review point. Fix: name the person and the check.
• A goal like 'help with sales'. Fix: write the result in one sentence with a time and a format.

Exercise

• Fill in the eight parts for your first use case.
• Read it aloud and apply the stop test.
• Pass condition: all eight parts filled, on one page, with a named person at the review point.