that-depends has no agent instructions file #69

What

that-depends has no AGENTS.md and no CLAUDE.md. It is the only repo in the org
without one, and it never had one: gh api repos/modern-python/that-depends/commits?path=CLAUDE.md
and the same for AGENTS.md both return empty. This is not fallout from the org-wide
rename in #51, which only touched repos that already had the file. It was never
onboarded.

It also has no CONTEXT.md and no docs/adr/.

Why it matters more here than anywhere else

that-depends is the org's most-used package and its only repo with real
contributor traffic. Across all PRs: 9 distinct authors, with xelandernt at 54 and
lesnik512 a minority at 28 of 100. Every other repo in the org is single-author
except fastapi-sqlalchemy-template.

So this is the one repo where an agent works alongside other people's changes, on the
codebase with the largest public surface, with zero steering.

Scope

Write an AGENTS.md describing the repo as it actually is, not a copy of
modern-di's conventions:

• It runs mypy and pyrefly in addition to ruff and ty (lint-ci), which is
  already noted in .github/AGENTS.md under Tooling.
• Its docs are on Read the Docs (.readthedocs.yaml), not the org MkDocs setup.
• Its PR traffic is majority-external, so its workflow section should describe review
  by a second party, which no other repo in the org has.
• It carries context7.json and a .pre-commit-config.yaml, neither of which appear
  elsewhere in the org.

Explicitly not in scope

• Its PR template stays exactly as it is. .github/PULL_REQUEST_TEMPLATE.md is
  the only template in the org measurably in use: xelandernt fills it in 8 of 9
  PRs, checklist included. It is a local copy of the generic form differing only in
  the mypy/pyrefly line, and that is a legitimate reason to stay local.
• Not the PR-body-as-spec convention. That convention assumes a single agent
  author writing the body for its own benefit. This repo has human reviewers and
  human PR authors, and the template that serves them already works.
• CONTEXT.md and docs/adr/ are separate questions; do not create them speculatively.

Revisit trigger

None; this is a gap to close, not a decision to revisit.