diff --git a/tools/sbom-diff-and-risk/PYPI_DESCRIPTION.md b/tools/sbom-diff-and-risk/PYPI_DESCRIPTION.md
new file mode 100644
index 0000000..1c3aff8
--- /dev/null
+++ b/tools/sbom-diff-and-risk/PYPI_DESCRIPTION.md
@@ -0,0 +1,61 @@
+# sbom-diff-and-risk
+
+`sbom-diff-and-risk` is a local, deterministic CLI for comparing two SBOMs or dependency manifests and producing review-friendly reports.
+
+It is designed for conservative supply-chain review workflows:
+
+- compare `before` and `after` dependency inventories
+- identify added, removed, and changed components
+- apply heuristic risk buckets to new and changed dependencies
+- emit JSON, Markdown, and SARIF outputs
+- keep default runs local-file based and deterministic
+
+## Supported inputs
+
+- CycloneDX JSON
+- SPDX JSON
+- `requirements.txt`
+- `pyproject.toml` via PEP 621 `[project]` metadata
+- `pyproject.toml` dependency groups via PEP 735 `[dependency-groups]`
+
+## Output formats
+
+- `report.json`
+- `report.md`
+- `report.sarif`
+
+## Install
+
+```bash
+python -m pip install sbom-diff-and-risk
+```
+
+## Quick start
+
+```bash
+sbom-diff-risk compare \
+  --before before.sbom.json \
+  --after after.sbom.json \
+  --format auto \
+  --out-json report.json \
+  --out-md report.md
+```
+
+## Defaults and scope
+
+- default operation is local and deterministic
+- no hidden network access occurs unless enrichment is enabled explicitly
+- no CVE or vulnerability database integration is performed
+- risk buckets are heuristic review signals, not security verdicts
+
+Optional enrichment can be enabled explicitly for:
+
+- PyPI provenance and integrity signals
+- OpenSSF Scorecard signals
+
+## Typical use cases
+
+- compare two release SBOMs during code review
+- review dependency manifest changes in CI
+- produce machine-readable and reviewer-readable change reports
+- add conservative policy gates around dependency changes
diff --git a/tools/sbom-diff-and-risk/pyproject.toml b/tools/sbom-diff-and-risk/pyproject.toml
index a6c42ee..35cf223 100644
--- a/tools/sbom-diff-and-risk/pyproject.toml
+++ b/tools/sbom-diff-and-risk/pyproject.toml
@@ -5,18 +5,36 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "sbom-diff-and-risk"
 version = "0.4.1"
-description = "Local, deterministic SBOM diff and heuristic risk reporting."
-readme = "README.md"
+description = "Deterministic SBOM diff CLI with heuristic risk reporting."
+readme = { file = "PYPI_DESCRIPTION.md", content-type = "text/markdown" }
 requires-python = ">=3.11"
 license = "MIT"
 authors = [
   { name = "OpenAI Codex" }
 ]
+keywords = ["sbom", "supply-chain", "cyclonedx", "spdx", "dependencies"]
+classifiers = [
+  "Development Status :: 3 - Alpha",
+  "Environment :: Console",
+  "Intended Audience :: Developers",
+  "Operating System :: OS Independent",
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3 :: Only",
+  "Programming Language :: Python :: 3.11",
+  "Topic :: Security",
+  "Topic :: Software Development :: Libraries :: Python Modules",
+]
 dependencies = [
   "packaging>=24.0",
   "PyYAML>=6.0",
 ]
 
+[project.urls]
+Homepage = "https://github.com/stacknil/scientific-computing-toolkit"
+Repository = "https://github.com/stacknil/scientific-computing-toolkit"
+Issues = "https://github.com/stacknil/scientific-computing-toolkit/issues"
+Releases = "https://github.com/stacknil/scientific-computing-toolkit/releases"
+
 [project.optional-dependencies]
 dev = [
   "pytest>=8.0",