feat(mcp): add prerequisite-chain hints to create tool descriptions

[joshrotenberg]

Summary

Add prerequisite workflow hints to MCP tool descriptions for create/provisioning operations. This guides LLM agents through multi-step workflows by telling them what to validate before calling a create tool.

Pattern borrowed from redis/mcp-redis-cloud, which includes guidance like:

"Prerequisites: 1) Verify payment method via get-current-payment-methods. 2) Validate modules against get-database-modules. 3) Validate regions using get-pro-plans-regions."

Tools to update

Cloud

• cloud_create_subscription -- prerequisites: check payment methods, validate regions, check modules
• cloud_create_database -- prerequisites: get subscription, validate modules, check available versions
• cloud_create_fixed_subscription -- prerequisites: list plans, check regions
• cloud_create_fixed_database -- prerequisites: get subscription, list plans, validate modules

Enterprise

• create_enterprise_database -- prerequisites: check cluster status, list modules, check license capacity
• create_enterprise_user / create_enterprise_role / create_enterprise_acl -- prerequisites: list existing roles/ACLs for reference

Approach

Update the .description() string on each ToolBuilder to append a "Prerequisites:" section. No functional changes -- description-only updates.

Priority

P3 -- Nice UX improvement for AI agents, no urgency.