fix(mcp): avoid repeated tool schema materialization

[mattzcarey]

Summary

• cache MCP input/output JSON Schema conversion for unchanged live connection catalogs while continuing to return fresh AI tool records and execute closures
• add Think.includeMcpTools, defaulting to true, so transport-only integrations such as Code Mode can skip direct MCP AI-tool materialization without disabling connection restore, discovery, waiting, raw listing, or calls
• add regression coverage for a 313-tool catalog, cache invalidation, failed conversions, and transport-only connector access
• document the new setting and ship patch changesets for agents and @cloudflare/think

Why

Think currently calls getAITools() before beforeTurn(), so an activeTools filter cannot prevent every MCP input and output schema from being converted to Zod. Large Code Mode-only catalogs therefore pay hundreds of conversions on every turn despite exposing no direct MCP tools to the model.

This change avoids conversion entirely for transport-only Think agents and reuses converted schemas for direct MCP exposure until the catalog or affected schema source changes.

Testing

• pnpm --filter agents exec vitest --run --project workers src/tests/mcp/client-manager.test.ts
• pnpm --filter @cloudflare/think exec vitest --run -c src/tests/vitest.config.ts src/tests/mcp-tool-materialization.test.ts
• full agents package test suite
• full @cloudflare/think package test suite
• pnpm exec nx affected -t build test --base=origin/main
• pnpm run check

Closes #1938

---

[changeset-bot]

🦋 Changeset detected

Latest commit: 7f1054a

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 3 packages

Name	Type
agents	Patch
@cloudflare/think	Patch
@cloudflare/agent-think	Patch

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[devin-ai-integration]

✅ Devin Review: No Issues Found

Devin Review analyzed this PR and found no bugs or issues to report.

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commit: 7f1054a