RFC: Add AI tool use policy in code of conduct

CODE_OF_CONDUCT.md

@@ -32,6 +32,43 @@ And if someone takes issue with something you said or did, resist the urge to be
 
 The enforcement policies listed above apply to all official embedded WG venues; including the official Matrix room (#rust-embedded:matrix.org) and linked IRC channels (#rust-embedded on Libera); and all GitHub repositories under rust-embedded.
 
+## AI Tool Use Policy
+
+When using AI tools for contributing, human oversight remains critical.
+
+- **You are responsible for your contributions.** It is your responsibility to review, test, and understand everything you submit. Submitting unverified or low-quality machine-generated content creates an unfair review burden on the community and is not an acceptable contribution. Contributors should review and understand their own submissions before asking the community to review their code.
+- **Start with small contributions.** Open source communities operate on trust and reputation. Reviewing large contributions is expensive, and AI tools tend to generate large contributions. We encourage new contributors to keep their first contributions small, specifically below 150 additional lines of non-test code insertions, until they build personal expertise and maintainer trust before taking on larger changes.
+- **Be transparent about your use of AI.** When a contribution has been significantly generated by an AI tool, we ask you to note this in your pull request description. This transparency helps the community develop best practices and understand the role of these new tools.
+- **Limit AI tools for reviewing.** As with creating code, reviewers may use AI tools to assist in providing feedback, but not to wholly automate the review process. Particularly, AI may not make the final determination on whether a contribution is accepted or not.
+
+This policy extends beyond code contributions and includes, but is not limited to, the following kinds of contributions:
+
+- Code, usually in the form of a pull request.
+- RFCs or design proposals.
+- Issues or security vulnerabilities.
+- Comments and feedback on pull requests.
+
+### Extractive Changes
+
+Sending patches, PRs, RFCs, comments, etc., is not free – it takes a lot of maintainer time and energy to review those contributions! We see the act of sending low-quality, un-self-reviewed contributions to the Rust Embedded WG project as “extractive.” It is an attempt to extract work from the community in the form of review comments and mentorship, without the contributor putting in comensurate effort to make their contribution worth reviewing.
+
+Our golden rule is that a contribution should be worth more to the project than the time it takes to review it. If a maintainer judges that a contribution is extractive (i.e., it is generated mainly with tool-assistance or requires significant revision), they
+should copy-paste the following response, add the `extractive` label if applicable, and refrain from further engagement:
+
+> This PR appears to be extractive, and requires additional justification for why it is valuable enough to the project for us to review it. Please see our developer policy on AI-generated contributions: https://github.com/rust-embedded/wg/blob/master/CODE_OF_CONDUCT.md#AI-Tool-Use-Policy
+
+Other reviewers should use the label to prioritize their review time.
+
+The best ways to make a change less extractive and more valuable are to reduce its size or complexity or to increase its usefulness to the community. These factors are impossible to weigh objectively, and our project policy leaves this determination up to the maintainers of the project, i.e. those who are doing the work of sustaining the project.
+
+If a contributor responds but doesn’t make their change meaningfully less extractive, maintainers may lock the conversation.
+
+### Copyright
+
+AI systems raise many questions around copyright that have yet to be answered. Our policy on AI tools is similar to our copyright policy: Contributors are responsible for ensuring that they have the right to contribute code under the terms of our license, typically meaning that either they, their employer, or their collaborators hold the copyright. Using AI tools to regenerate copyrighted material does not remove the copyright, and contributors are responsible for ensuring that such material does not appear in their contributions. Contributions found to violate this policy will be removed just like any other offending contribution.
+
 *Adapted from the [Node.js Policy on Trolling](http://blog.izs.me/post/30036893703/policy-on-trolling) as well as the [Contributor Covenant v1.3.0](https://www.contributor-covenant.org/version/1/3/0/).*
 
+*AI Tool Use Policy adapted from the proposed [LLVM AI tool policy: start small, no slop](https://discourse.llvm.org/t/rfc-llvm-ai-tool-policy-start-small-no-slop/88476)*
+
 [wg]: https://github.com/rust-embedded/wg#organization