book/tools contains production tooling for the MLSysBook source tree. These tools are part of how the book is built, checked, generated, audited, and released. Some are called by humans, some by CI, some by Binder commands, and some by Quarto-adjacent generation workflows.

Do not delete, rename, or move anything under this tree only because it looks like a one-off script. First audit actual use in QMD files, Binder commands, CI, release scripts, documentation, and generated-asset workflows.

Production Policy

Treat book/tools as book infrastructure, not scratch space.
Before relocating or removing a tool, search for call sites with rg, update callers and documentation, and run the relevant validation command.
Prefer stable modules or Binder-facing entrypoints for new book dependencies. Scripts may remain as compatibility entrypoints when they are already part of production workflows.
Generated assets should record their source tool in the nearby README or comments so future editors can regenerate rather than hand-edit them.
Tooling that depends on external packages should document the runtime command and any special environment setup.

Current Areas

Area	Purpose
`scripts/`	Python and shell entrypoints for generation, maintenance, release, and Quarto-adjacent workflows.
`audit/`	Durable audit records and audit helpers used to track book quality work.
`dependencies/`	Dependency and environment documentation.
`git-hooks/`	Repository hook documentation and related setup.

Figure Tool Ownership

Historically, the book used mlsysim.viz for two different kinds of plotting:

Simulator visualizations that understand mlsysim objects, such as roofline, distributed roofline, and evaluation scorecard plots.
Book publication style helpers, such as the shared palette, matplotlib style, and one-line setup_plot() helper used by many QMD figure blocks.

The simulator-aware plotting functions should stay in mlsysim. The book publication style helpers are owned by Book Tools because they are book production policy rather than simulator domain logic. Current QMD figure-style imports should use book.tools.figures.style.

Current figure-tool structure:

book/tools/
  figures/
    style.py        # COLORS, set_book_style(), setup_plot(), web DPI
    margin/         # margin SVG devices and inline-ready drawing helpers
  scripts/
    margin_figures/ # generation, inventory, insertion, QA script entrypoints

Recommended next migration:

book/tools/
  figures/margin/
    inline.py       # optional Quarto-facing margin_svg() helper

Compatibility policy:

New and migrated book code imports book style from book.tools.figures.style.
mlsysim.viz may continue to re-export the style helpers only as a compatibility bridge for older snippets and standalone simulator tutorials.
Add an inline margin helper only if the book starts rendering margin figures from executable cells instead of committed SVG assets.

This keeps simulator-object plotting in mlsysim while keeping book publication policy in Book Tools.