docs: investigate commercial services behind thin repositories

CONTRIBUTING.md

@@ -58,7 +58,8 @@ Link to the PyPI package page. If the project has a GitHub repo, append it after
 ### General rules
 
 - Use `https://` URLs only.
-- GitHub repository URLs are strongly preferred and are a major positive relevance signal.
+- GitHub repositories containing substantive implementation are strongly preferred and are a
+  major positive relevance signal.
   Projects with a verifiable GitHub repository are easier to evaluate for source availability,
   documentation, activity, maintenance, and community adoption, and they receive automated
   tracking of stars, activity, and archive status on
@@ -66,8 +67,9 @@ Link to the PyPI package page. If the project has a GitHub repo, append it after
 - A public GitHub repository containing the substantive implementation is preferred. Use it
   as the main URL, or append the exact `[GitHub](https://github.com/owner/repo)` suffix when
   the project has a separate website. Repository-less commercial services are considered only
-  under the eligibility rules below. A valid GitHub repository mentioned in either place
-  receives the same relevance consideration.
+  under the eligibility rules below. A substantive GitHub repository mentioned in either place
+  receives the same relevance consideration; repository existence alone does not establish
+  commercial eligibility or functional-section placement.
 - Use short, meaningful tags. Each concept must have its own backtick pair; for example,
   use `` `Python` `C++` `` rather than `` `Python, C++` ``.
 - The description must end with a period (before the `[GitHub]` link, if present).
@@ -100,13 +102,22 @@ integration, examples, generated-data, or marketing repository—are repository-
 eligibility check. They must publish pricing and free-tier limits, as well as public documentation,
 methodology, or usage examples. Their entries must use a stable HTTPS URL without affiliate or
 tracking parameters, have a concise, factual, non-promotional description, and be placed in the
-**Commercial & Proprietary Services** section. Backtick tags are optional in that section. For
-example:
+**Commercial & Proprietary Services** section. Use the service name and website as the main
+link; when a supporting repository exists, append it as the exact `[GitHub](...)` suffix.
+Describe the service and relevant free-tier limits, not merely its SDK. Backtick tags are
+optional in that section. For example:
 
 ```markdown
 - [Project Name](https://project.example) - Concise factual description ending with a period.
+- [Service Name](https://service.example) - Factual service description with relevant free-tier limits. [GitHub](https://github.com/owner/client)
 ```
 
+Reviewers inspect representative source files to establish whether advertised functionality is
+implemented publicly or merely accessed through a proprietary service, and follow linked service
+documentation and pricing pages. Small size, few stars, or recent creation alone do not make a
+repository thin. An open-source SDK license does not make the service open source; substantive
+public implementation may qualify for a functional section even with a paid hosted version.
+
 Only a repository containing substantive implementation supports placement in a functional
 section. Commercial submissions without a qualifying permanent free tier—including paid-only,
 trial-only, demo-only, and waitlist-only offerings—are `REJECT`. Reserve `NEEDS CHANGES` for