docs: clarify stats and composite configuration

[ryan-lempka]

Clarify that stats report token usage and latency, not dollar costs. Document the six missing composite settings and correct the session hash fallback guidance.

Summary by CodeRabbit

• Documentation
  • Expanded composite route reference documentation with classifier configuration options, their defaults and constraints, and optional stage handoff notes.
  • Clarified that message-hash fallback works with either supported trigger.
  • Updated escalation router observability guidance: stats include token usage and latency, but not dollar costs, which must be calculated separately from recorded usage and model pricing. Classifier stats continue to report judge-call token usage and latency.

[github-actions]

PR Preview Action v1.8.1
🚀 View preview at https://NVIDIA-NeMo.github.io/Switchyard/pr-preview/pr-860/
Built to branch gh-pages at 2026-09-28 16:31 UTC. Preview will be ready when the GitHub Pages deployment is complete.

[coderabbitai]

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Walkthrough

The routing documentation now describes composite classifier options and stage handoff notes. It also clarifies which escalation-router token usage and latency statistics are reported, and that dollar costs are not included.

Changes

Routing reference documentation

Layer / File(s)	Summary
Composite-route configuration reference docs/reference/toml_schema.md	The composite classifier table documents option defaults and constraints, and clarifies message_hash_fallback behavior. The stage table documents optional handoff_notes.
Escalation-router statistics reference docs/routing_algorithms/escalation_router_routing.md	The snapshot description specifies token usage and latency reporting. It clarifies that dollar costs are excluded and must be calculated separately using recorded usage and model pricing.

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: 🔵 Low · up to 7f1b3

Clarify the statistics buckets before merging so readers calculate and interpret judge-call usage correctly.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the documentation changes to statistics and composite configuration. It is concise and directly related to the main changes.

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_{A rabbit reads the routing page
And finds new fields upon the stage
Token counts and latency shine
While costs stay out of the line
It hops away, docs clear and bright}

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

[coderabbitai]

Actionable comments posted: 1

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• 🪄 Fix CodeRabbit comments on this PR

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Inline comments:
Review comments at @docs/routing_algorithms/escalation_router_routing.md:
- Line 158: Update the judge-call statistics wording near “routing overhead” to
distinguish classifier stats from aggregate overhead: state that token usage and
per-call latency are recorded in classifier stats, while aggregate routing
overhead includes judge-call latency only. Preserve the note that dollar costs
are excluded and calculated separately.

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📥 Commits

Reviewing files that changed from the base of the PR and between ccac48e and 7f1b303.

📒 Files selected for processing (2)

• docs/reference/toml_schema.md
• docs/routing_algorithms/escalation_router_routing.md

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