Fix Security Guard Agent to call noop when no security concerns found

[Copilot]

Security Guard Agent was triggering "No Safe Outputs Generated" warnings when correctly finding no security issues. The workflow exited silently instead of signaling explicit completion.

Changes

• Added noop: to safe-outputs config - Enables the agent to explicitly signal "analyzed, nothing to report"
• Updated prompt instructions - Replaced "exit gracefully" with "call noop" in decision points and example scenarios

Before/After

# Before - no way to signal successful completion without findings
safe-outputs:
  add-comment:
    max: 1

# After - agent can now explicitly signal no action needed
safe-outputs:
  add-comment:
    max: 1
  noop:

Prompt now instructs:

- **NO SECURITY CONCERNS FOUND**: Call `noop` to explicitly signal that no security issues were detected.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[agentics] Security Guard Agent 🛡️ failed</issue_title>
<issue_description>### Workflow Failure

Workflow: Security Guard Agent 🛡️
Branch: HEAD
Run URL: https://github.com/githubnext/gh-aw/actions/runs/21409179321

⚠️ No Safe Outputs Generated: The agent job succeeded but did not produce any safe outputs. This typically indicates:

• The safe output server failed to run
• The prompt failed to generate any meaningful result
• The agent should have called noop to explicitly indicate no action was taken

Action Required

Debug this workflow failure using the agentic-workflows agent:

/agent agentic-workflows

When prompted, instruct the agent to debug this workflow failure.

Generated from Security Guard Agent 🛡️

• expires on Feb 3, 2026, 6:30 PM UTC

<agent_instructions>investigate this</agent_instructions>

Comments on the Issue (you are @copilot in this section)

Custom agent used: agentic-workflows
GitHub Agentic Workflows (gh-aw) - Create, debug, and upgrade AI-powered workflows with intelligent prompt routing

• Fixes [agentics] Security Guard Agent 🛡️ failed #12082

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[pelikhan]

Noop should be a builtin. Fixing in other PR