docs(rfc): RFC 0032 drafted — query-schema + cost-model resource for the MCP surface

[jensholdgaard]

What

RFC 0032 — Query-schema and cost-model resource for the MCP surface, entering the ladder at drafted. Docs-only (one RFC file + a SUMMARY.md line); no code.

Implements the scope agreed on #465, amending the accepted RFC 0027: a second MCP resource (ourios://query-schema, versioned JSON) that gives an agent-consumer the field vocabulary (the RFC 0002 §7 DSL fields — not raw Parquet columns, per hazard §4.6), the OTel 1–24 severity scale with name bands pinned to SeverityName::floor/ceil, the per-deployment promoted attributes (the half an agent cannot guess), and the query-class cost model — the durable L1–L6 structure as tiers (index_backed / pruned / scan), never benchmark numbers.

Key grounded choices:

• Index-backed classification matches what the writer actually blooms (writer.rs: template_id, trace_id, span_id, promoted columns); severity is statistics, and RFC0032.4 gates against ever claiming bloom for it.
• Promoted-attribute equality is index-backed only for keys promoted in this instance; any other attribute key classifies scan.
• Tool descriptions get exactly one advisory sentence pointing at the resource; the tiering lives only in the machine-readable resource (the MCP query surface: expose the stored-log query schema as a resource (RFC 0027 amendment) #465 placement rule).
• Dynamic promoted-attribute fork adopted (static-only recorded as the rejected alternative in §4).

§5 has six testable criteria (RFC0032.1–.6) riding the RFC 0027 in-process MCP harness pattern, including config-sensitivity and the read-only contract.

Checks run

mdbook build clean; rendered page verified. No code touched.

🤖 Generated with Claude Code

https://claude.ai/code/session_01WQY9wfrfRggqSpMLH8Xj3Y

[coderabbitai]

Warning

Review limit reached

@jensholdgaard, you've reached your PR review limit, so we couldn't start this review.

Next review available in: 44 minutes

Enable usage-based reviews in Billing to review now. Otherwise, wait until the next included review is available.
You're only billed for reviews past your plan's rate limits ($0.25/file).

How can I continue?

After more reviews become available, a review can be triggered using the @coderabbitai review command as a PR comment. Alternatively, push new commits to this PR.

To avoid repeated limits, reduce automatic review volume by pausing incremental auto-reviews earlier, using label-based review opt-in, excluding WIP or generated PR titles, or requesting reviews manually when the PR is ready. If your team needs uninterrupted high-volume reviews, an organization admin can enable usage-based reviews.

How do review limits work?

CodeRabbit enforces per-developer PR review limits for each organization. Most developers receive the normal plan review availability.

For paid Pro and Pro+ PR reviews, CodeRabbit uses adaptive limits for sustained high-volume activity. When a developer's recent PR review activity reaches the 95th percentile or higher among CodeRabbit users, additional reviews become available more gradually as earlier reviews age out of the rolling window.

Please refer docs for additional details.

Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: c6c3c7a6-4f4b-451d-be75-50531e8660d7

📥 Commits

Reviewing files that changed from the base of the PR and between ff67d03 and dcf9c2c.

📒 Files selected for processing (2)

• docs/SUMMARY.md
• docs/rfcs/0032-query-schema-cost-model-resource.md

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch rfc0032-drafted

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[Copilot]

Pull request overview

Drafts RFC 0032 to extend the RFC 0027 MCP query surface with an additional resource (ourios://query-schema) that provides a machine-readable query field vocabulary plus a structural (non-numeric) cost-tier classification to help agent consumers form correct and efficient queries.

Changes:

• Add RFC 0032 document describing the ourios://query-schema JSON resource (fields, severity scale, promoted attributes, and cost model tiers).
• Add RFC 0032 to the mdBook table of contents (docs/SUMMARY.md).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
docs/SUMMARY.md	Adds RFC 0032 to the RFC index for navigation/build inclusion.
docs/rfcs/0032-query-schema-cost-model-resource.md	Introduces the drafted RFC describing the new MCP query-schema + cost-model resource and its acceptance criteria/testing approach.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.