`safe-outputs.actions` custom action tools not exposed to agent MCP toolset

[susmahad]

safe-outputs.actions custom action tools not exposed to agent MCP toolset

Description

When configuring a custom action via safe-outputs.actions, the tool appears in the compiled workflow's tool list but is not available to the agent at runtime.

Configuration

safe-outputs:
  actions:
    upload_report:
      uses: actions/upload-artifact@v4
      description: Upload the CSDL Assessment Report as a workflow artifact

Expected Behavior

The upload_report tool should be available to the agent and callable like other safe-output tools (add_comment, create_pull_request, etc.).

Actual Behavior

The agent reports: upload_report tool not in toolset

Agent output:

⚠️ Report artifact upload skipped (`upload_report` tool not in toolset); report file `CSDL_Assessment_Report_20260414_195246.md`

Evidence from Compiled Workflow

The tool IS correctly compiled:

1. Listed in the prompt's tool list:

   Tools: add_comment(max:5), create_pull_request, push_to_pull_request_branch, missing_tool, missing_data, noop, upload_report
   

2. Action step is generated with correct conditional:

   - name: Upload the CSDL Assessment Report as a workflow artifact
     id: action_upload_report
     if: steps.process_safe_outputs.outputs.action_upload_report_payload != ''
     uses: actions/upload-artifact@v4
     with:
       name: ${{ fromJSON(steps.process_safe_outputs.outputs.action_upload_report_payload).name }}
       path: ${{ fromJSON(steps.process_safe_outputs.outputs.action_upload_report_payload).path }}

3. Environment variable is set:

   GH_AW_SAFE_OUTPUT_ACTIONS: "{\"upload_report\":\"upload_report\"}"
   

Analysis

The compiled workflow correctly includes:

• The tool in the <safe-output-tools> section of the prompt
• The action step with proper conditional execution
• The environment variable mapping

However, unlike built-in safe-outputs (create_pull_request, add_comment), there is no dedicated prompt file generated for custom actions (e.g., safe_outputs_upload_report.md). This may be why the agent doesn't recognize the tool schema.

Workaround

Currently relying on the agent's general artifacts to capture the report file, but this makes it harder to find after downloading (buried in agent artifacts vs. a dedicated named artifact).

Version

• gh-aw: v0.68.2

Related

• PR feat: mount custom GitHub Actions as safe output tools via safe-outputs.actions #21752: feat: mount custom GitHub Actions as safe output tools via safe-outputs.actions