Agentic workflow patterns (practical)

This book assumes you use an assistant as a productivity multiplier, not a substitute for engineering standards. These patterns reliably improve output quality and reduce back-and-forth.

1) Don’t start from empty

Assistants work best with a real package skeleton and a real test harness.

Minimum baseline

DESCRIPTION, NAMESPACE, R/, tests/
testthat wired up
A single “golden path” test you can run quickly

Commands (copy/paste)

# Use in a new package repo
usethis::use_testthat(edition = 3)
usethis::use_roxygen_md()
usethis::use_package_doc()

2) Give the agent a constitution (project rules)

Write down conventions once so every patch is consistent.

Good places for rules:

AGENTS.md (agent-facing)
CONTRIBUTING.md (human-facing)
docs/ (domain and workflow notes)

Rule examples that pay off:

Namespacing: pkg::fun in production code
Errors: cli::cli_abort() with actionable messages
Tests: regression test for every bug fix
Scope: minimal diffs, no drive-by refactors

3) “Skeleton first” beats “explain everything”

When a change is non-trivial, create a small skeleton for the agent to fill:

File path(s) you want touched
Function signatures (inputs/outputs)
A short checklist of behaviors and edge cases

This prevents unnecessary files, keeps scope tight, and makes review easier.

4) Strategic context beats dumping the repo

Instead of pasting everything, provide:

The function(s) being changed
The tests that cover them (or the place tests should go)
The exact error/log snippet
One example call that demonstrates the desired behavior

If the agent needs more, it can ask for it.

5) Documentation is a control surface

Treat docs as part of the workflow, not an afterthought:

Keep roxygen close to behavior (params/return/errors)
Put “why” and “how to use” notes in docs/ where the agent can reference them
Update docs in the same patch as behavior changes

Copy/paste: repeatable loop

Plan -> Patch -> Verify

Verify:
- devtools::document()
- devtools::test()
- devtools::check()