What the two built-in reasoning agents are for, how they are deployed and when a custom agent fits.
From Ultra Transcenders AB-900 by Tony Rough (coming November 2026)
Microsoft ships two reasoning agents with the licence, and custom agents fill the gaps for specific business tasks.
Researcher handles complex, multi-step research. It draws on the web and on work content the user can access (files, emails, meetings, chats, and Copilot connector content) and returns a structured report with cited sources, visuals and sections. It spends longer than standard chat: simple queries take under five minutes and complex ones 10 to 45 minutes. Learn documents a limit of 25 queries per user per month. Standard Copilot chat remains the better choice for a quick summary, short reply or light brainstorming.
Analyst reasons over raw data like a data analyst: it runs code, works across multiple spreadsheets and produces insights and visualisations. Learn’s Researcher FAQ points users to Analyst for Excel-related tasks.
Custom agents suit repeatable, scenario-specific work grounded in the organisation’s own content. Learn’s examples include project FAQ agents, product documentation assistants, onboarding agents and writing or presentation coaches (built in Agent Builder), and customer support, IT help desk triage and CRM sales assistants (built in Copilot Studio).
| Need | Choose |
|---|---|
| Deep, cited research across web and work data | Researcher |
| Analysis of raw data and spreadsheets with code and charts | Analyst |
| A lightweight Q&A agent over team content, for yourself or a small team | Agent Builder agent |
| Department-wide or external agents, multi-step workflows, connectors, autonomous actions, dev/test/production lifecycle | Copilot Studio agent |
| Questions over the content of one SharePoint site | SharePoint agent |
Common trap: Trying to make Researcher available only to a pilot group through the agent’s user assignment or the agent User access setting - Researcher and Analyst can’t be assigned to selected users, and agent settings don’t govern them; the only admin control is blocking them for the entire tenant.
This note is one section of Ultra Transcenders AB-900: Microsoft 365 Copilot and Agent Administration Fundamentals, an independent study guide that explains every topic the exam covers by technology, with comparison tables, diagrams and the common traps, plus a glossary linked to Microsoft Learn.
Due on Amazon in November 2026, in Kindle and paperback editions.
About the book · AB-900 terms in the glossary · All AB-900 study notes
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