feat(mcp): add composed multi-step tools

[joshrotenberg]

Summary

Add higher-level tools that compose multiple API calls into useful operations.

Examples

Redis Cloud

• get_subscription_summary - subscription + all databases + stats in one call
• compare_databases - compare configs between two databases
• check_subscription_health - databases + alerts + recent tasks

Redis Enterprise

• get_cluster_health - cluster + nodes + alerts + stats
• get_database_overview - database + endpoints + shards + stats
• diagnose_database - comprehensive health check

Cross-Platform

• list_all_databases - aggregate from Cloud + Enterprise
• find_database - search by name/pattern across platforms

Implementation

• Build on existing atomic tools
• Return structured summaries
• Consider caching for repeated lookups
• Handle partial failures gracefully

Related

• PR feat!: rewrite redisctl-mcp using tower-mcp framework #597 added atomic building-block tools
• feat(mcp): add write tools with read-only mode filtering #601 covers write tools

[joshrotenberg]

Closing as superseded by #718 (Agent Skills).

After discussion, hardcoded composed tools (Rust functions that chain multiple API calls into a fixed workflow) are the wrong abstraction here. They're rigid, presumptuous about user workflows, and require Rust code changes + recompilation for every new composition.

The skills approach (#718) is better on every axis:

• Flexibility: users write their own workflows as markdown playbooks without touching Rust
• Transparency: the agent reasons at each step rather than returning a black-box blob
• Customization: users can tailor workflows to their specific environments and thresholds
• Maintenance: markdown files vs. Rust code with error handling for partial failures

The one tradeoff (fewer round-trips with composed tools) isn't worth the rigidity -- MCP tool calls are cheap and agents handle multi-step flows well.

The prerequisite-chain hints added in #810 cover the immediate need of guiding agents through multi-step create workflows.