Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/johnnichev/selectools/agents-mdgit clone --depth 1 https://github.com/johnnichev/selectoolsWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.01252 | $0.01252 |
| Opus 5 | $0.00626 | $0.00626 |
| Sonnet 5 | $0.00250 | $0.00250 |
| Haiku 4.5 | $0.00125 | $0.00125 |
Grade A, and why
selectools AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Selectools -- Agent Instructions
Commands
# Test (MUST pass before any commit)
pytest tests/ -x -q
pytest tests/ -k "not e2e" -x -q # no API keys needed
# Format + lint (MUST run before commit — replaces Black + isort + flake8)
ruff format src/ tests/
ruff check src/ tests/ --fix
# Type check
mypy src/
# Security (MUST pass before release tags)
bandit -r src/ -ll -q -c pyproject.toml
# Docs
cp CHANGELOG.md docs/CHANGELOG.md && mkdocs build
Stack
- Python 3.9+ (CI: 3.9, 3.10, 3.11, 3.12, 3.13)
- pip + setuptools, src-layout:
src/selectools/ - pytest (5000+ tests), Ruff (format + lint), mypy
- MkDocs Material for docs, deployed to GitHub Pages
Boundaries
Always (do without asking)
- Run
ruff formatandruff check --fixon every modified file - Run
pytest tests/ -k "not e2e" -x -qafter implementation changes - Add type hints to all public APIs
- Add a regression test for every bug fix
- Apply
@betastability marker to new public symbols - Use
response_msg.content or ""when reading provider content
Ask First
- Adding new fields to
AgentConfig,AgentResult, orAgentObserver - Adding new
StepTypevalues toAgentTrace - Modifying
agent/core.py(the main agent loop) - Changing public API signatures on
@stablesymbols - Adding new dependencies to
pyproject.toml
Never
- Push directly to main -- MUST use PR workflow
- Push to remote without explicit user request
- Call real LLM APIs in unit tests -- use
RecordingProvideror mocks - Use
datetime.utcnow()-- MUST usedatetime.now(timezone.utc) - Use
x = x or defaultwhen0,"", or[]are valid values - Create
ThreadPoolExecutor()per-call in async code -- use module singleton - Use
self.config.modelinastream()-- MUST useself._effective_model - Stringify
ToolCallobjects -- checkisinstance(chunk, str)first - Skip the
toolsparameter in providerstream()/astream()methods - Add co-author trailer lines to commits
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 96 lines · 1,252 tokens per session scan A e8d873464a94
selectools AGENTS.md is an instructions file published in the GitHub repository johnnichev/selectools (11 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 1,252 tokens to every session, about $0.0063 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
Doberman-Core AGENTS.md
Instructions for DobermanCore/Doberman-Core, covering claude.md — doberman operating manual, 0. on startup (every session), 1. what this repository is, 2. architecture & extension points and 3. prime directives (non-negotiable).
agent-guardrails-template copilot-instructions.md
Instructions for TheArchitectit/agent-guardrails-template, covering github copilot instructions, the four laws of agent safety, code generation rules, scope (mandatory) and production-first.
agent-guardrails-template CLAUDE.md
Instructions for TheArchitectit/agent-guardrails-template, covering project guidelines, 0. navigation maps (read first), 0.1 agent-gdui-2026 initialization context, 1. context & setup and 2. token-saving rules (strict).
FeatherlaneAI AGENTS.md
Instructions for ducnguyen67201/FeatherlaneAI, covering repository agent instructions, skills, architecture: rust backend is the source of truth, page integration expectations and implementation checklist.
agent47 AGENTS.md
Instructions for bmdhodl/agent47, covering agents.md, read this first: sdk memory, cofounder inbox, what this is and agent contract (mandatory).
agent47 CLAUDE.md
Instructions for bmdhodl/agent47, covering claude.md, read first, repo boundary, claude repo contract and what claude should optimize for here.