Builder lab · Module 4 · 55 min
Build a Healthcare Agent
Compose instruction, tools, explicit state, limits and stop conditions into a bounded loop — then diagnose a runaway trace and fix it in policy rather than in prompt wording.
After this module you can
Compose an instruction, a minimal tool set, explicit state, hard limits and stop conditions into a bounded agent loop — then read its trace, diagnose a runaway loop and fix it by changing policy rather than prompt wording.
- Say precisely what a loop adds over a single call, and what it costs.
- Write an agent goal narrow enough to have a terminal state.
- Choose the smallest tool set that can reach that goal.
- Name the state an agent must carry between iterations.
- Set step budgets, retry limits and stop conditions that make termination guaranteed.
- Diagnose a non-terminating trace and fix it in the loop policy.
Module 3 validated one proposed call. An agent proposes many, in sequence, on the basis of what earlier calls returned. Nothing about that changes who authorises a write.
Step 1
One-shot call vs a bounded loop
Same synthetic workflow, two architectures. Only one of them can act on what it learns.
Everything here is simulated. The follow-up coordinator, its patient and every tool result are synthetic fixtures. The loop is a pure function over your configuration — the same settings always produce the same trace.
# One call, one output request → LLM → structured follow-up plan (text/JSON) result : a proposal. Nothing is read, nothing is written. failure : the model guesses facts it was never given.
# Bounded loop, several calls
PLAN → "I need the patient's current medicines before proposing a review date"
CALL → get_patient_summary(SYN-004821)
OBSERVE → { current_medicines: [...], last_consultation: "2026-09-04" }
DECIDE → enough information? yes → propose the write
CALL → create_follow_up_task(...) [gated]
STOP → goal_complete | approval_required | budget_exhausted | errorSelect every true statement (3 or more, no wrong picks).
Select at least 3 true statements, with no incorrect picks.
0 of 7 steps complete
Sources & evidence · 4 sources
This module cites public or consensus guidance, scholarly literature, vendor documentation.
Content reviewed: September 2026. Publication dates of the individual sources are shown in each citation.
OpenAI — Function calling guide
The provider-level mechanics the loop wraps: proposal, execution, result, next turn.
Open sourceAnthropic — Building effective agents
Argues for the smallest viable composition of workflow and agent patterns, which is the position taken in this lab.
Open sourceXinzhe Li. A Review of Prominent Paradigms for LLM-Based Agents: Tool Use, Planning (Including RAG), and Feedback Learning. Proceedings of COLING 2025, pages 9760–9779.
Independent, peer-reviewed survey of tool-use, planning and feedback-learning paradigms — the non-vendor grounding for the agent-loop patterns described here. It does not establish that any one pattern is universally best.
Open sourceNIST AI Risk Management Framework — Generative AI Profile
Human oversight and bounded autonomy for consequential actions.
Open source