[Community] Close Stale Tools PRs

[mkmeral]

Part of Community Health & Ecosystem Strategy

Goal

We want to provide closure and a clear path forward for contributors with open tool PRs. We'll help them migrate to the new independent publishing model.

Requirements

Communication

For each open external tool PR:

1. Post a comment explaining:

   • We've changed our policy on external tools
   • Why (security, maintenance burden)
   • The new path forward (template + catalog)
   • Offer to help migrate their code to the template
   • Link to template repo
   • Link to extensibility docs

2. Give contributors some time to respond/migrate

3. Close out tools repo PRs

Acceptance Criteria

• Comment posted on all 34 open external tool PRs
• 2-week waiting period observed
• PRs closed with final comment
• Any questions from contributors addressed

Dependencies

• GitHub tool template [Community] GitHub Strands Extension Template sdk-python#1537
• Update tools repo README [Community] Update repository guidelines in README #374