[MCP] Add tool annotations for read-only and destructive tools

[manoahLinks]

Summary

No tool in the ListTools response carries MCP annotations, so clients cannot tell that mindvault_browse is read-only while mindvault_reset destroys local state.

Scope

• Keep the implementation aligned with the existing MindVault architecture.
• Add or update automated tests.
• Update docs when the change affects contributors, deployers, or agent users.

Acceptance criteria

• Every tool declares appropriate readOnlyHint, destructiveHint, and idempotentHint annotations plus a human-readable title.
• A test asserts each registered tool has annotations and that read-only tools are not marked destructive.
• Failure cases are deterministic and safe to show in issue-driven contributor work.
• Relevant local tests pass.

[RaymondAbiola]

@RaymondAbiola has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Hi! I'd like to work on this issue.

The requirements are clear, and I'm comfortable working across different parts of the stack, including frontend, backend, smart contracts, and developer tooling. I'll follow the project's conventions, keep the implementation clean, and ensure it's properly tested before submitting.

Thanks!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @RaymondAbiola to this issue.

[Adunola022]

@Adunola022 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I’m interested in contributing to this issue and am confident I can deliver a clean, efficient solution.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Adunola022 to this issue.