[aw] Breaking Change Documentation has no AI credits pricing for model (auto)

### Workflow Failure

**Workflow:** [Breaking Change Documentation](https://github.com/dotnet/runtime/blob/main/.github/workflows/breaking-change-doc.md)
**Branch:** main
**Run:** https://github.com/dotnet/runtime/actions/runs/33218722021
**Pull Request:** [#132763](https://github.com/dotnet/runtime/pull/132763)

> [!WARNING]
> **Model has no AI credits pricing**: The agent failed because model `auto` is not in the built-in pricing table and no default fallback pricing is configured. The AWF API proxy rejected every inference request with HTTP 400.

This is a **configuration issue** — retrying will not help. The model must have pricing before the workflow can run.

How to fix this

**Option 1 — Add pricing in the workflow frontmatter:**

```yaml
models:
providers:
github-copilot:
models:
'auto':
cost:
# Placeholder values — replace with actual pricing for this model
input: "0e0" # $0.00 per million input tokens
output: "0e0" # $0.00 per million output tokens
cache_read: "0e0" # $0.00 per million cache-read tokens
cache_write: "0e0" # $0.00 per million cache-write tokens
```

Use the provider key matching your engine: `github-copilot` (Copilot), `anthropic` (Claude), `openai` (Codex), or `google` (Gemini). Only `input` and `output` are required; the rest default to zero (or `output` for `reasoning`).

**Option 2 — Map the model to a known model using the `models` field:**

If `auto` is an alias for a model already in the built-in pricing table, use the `models` frontmatter field to provide the mapping:

```yaml
models:
'auto':
- claude-sonnet-4-5
```

**Option 3 — Switch to a model already in the built-in pricing table:**

Replace `auto` in the workflow frontmatter with a model name that the AWF pricing system recognizes (e.g. `claude-sonnet-4-5`, `gpt-4.1`, `gemini-2.0-flash`).

### Action Required

**Assign this issue to an agent** to debug and fix the issue.

Debug with any coding agent

Use this prompt with any coding agent (GitHub Copilot, Claude, Gemini, etc.):

````
Debug the agentic workflow failure using https://raw.githubusercontent.com/github/gh-aw/main/debug.md

The failed workflow run is at https://github.com/dotnet/runtime/actions/runs/33218722021
````

Manually invoke the agent

Debug this workflow failure using your favorite Agent CLI and the `agentic-workflows` prompt.

- Start your agent
- Load the `agentic-workflows` skill from `.github/skills/agentic-workflows/SKILL.md` or
- Type `debug the agentic workflow breaking-change-doc failure in https://github.com/dotnet/runtime/actions/runs/33218722021`

> [!TIP]
>
> Stop reporting this workflow as a failure
>
> To stop a workflow from creating failure issues, set `report-failure-as-issue: false` in its frontmatter:
> ```yaml
> safe-outputs:
> report-failure-as-issue: false
> ```
>
>

> Generated from [Breaking Change Documentation](https://github.com/dotnet/runtime/actions/runs/33218722021) · [◷](https://github.com/search?q=repo%3Adotnet%2Fruntime+is%3Aissue+%22gh-aw-workflow-id%3A+breaking-change-doc%22&type=issues)

Start with .github/workflows/breaking-change-doc.md and the failed run linked in the issue. Read debug.md and the agentic-workflows skill at .github/skills/agentic-workflows/SKILL.md before investigating how the auto model is configured. Done means the Breaking Change Documentation workflow can run without the missing-model-pricing failure.

Written by the indexing model from the issue text.