Feat agent mask

[ZeroZ-lab]

[!IMPORTANT]

1. Make sure you have read our contribution guidelines
2. Ensure there is an associated issue and you have been assigned to it
3. Use the correct syntax to link this PR: Fixes #<issue number>.

Summary

fix #27887

Screenshots

Before	After
...

only 1 tools

If the conditions are met, call two tools.

Checklist

• [ ] This change requires a documentation update, included: Dify Document
• [x] I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• [x] I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• [x] I've updated the documentation accordingly.
• [x] I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

[ZeroZ-lab]

/gemini review

[fdb02983rhy]

It might be better to simplify the logic by combining these two areas into one, since they seem somewhat redundant. Either way, it's a really nice feature!