Monte Carlo Storage Cost Analysis

Monte Carlo Storage Cost Analysis Skill

This skill analyzes a data warehouse for stale tables that can be removed to reduce storage costs. It delegates classification, safety scoring, and formatting to the analyze_storage_costs MCP tool, then presents the pre-formatted result verbatim and handles follow-up questions (category drill-downs, lineage checks).

Monte Carlo tool routing (required): Always call Monte Carlo MCP tools through this plugin's bundled server, whose fully-qualified tool names are mcp__plugin_mc-agent-toolkit_monte-carlo-mcp__<tool> (e.g. mcp__plugin_mc-agent-toolkit_monte-carlo-mcp__get_alerts). Bare tool names used in this skill (get_alerts, search, get_table, …) refer to that bundled server. If the session also has a separately-configured monte-carlo-mcp server, do not route to it — it may point at a different endpoint or credentials.

Reference file (use the Read tool to access it):

• Output contract and category keywords: references/output-structure.md

When to activate this skill

Activate when the user:

• Asks about storage costs, waste, or cleanup opportunities
• Wants to find unused, unread, or stale tables
• Asks "which tables can I drop?" or "what's costing us money?"
• Mentions storage optimization, cost reduction, or warehouse cleanup
• Wants to identify zombie tables, dead-end pipelines, or temporary/archive tables

When NOT to activate this skill

Do not activate when the user is:

• Just querying data or exploring table contents
• Creating or modifying monitors (use the monitoring-advisor skill)
• Investigating data quality incidents (use the prevent skill)
• Looking at pipeline performance or query cost (use the performance-diagnosis skill)

Prerequisites

The following MCP tools must be available (connect to Monte Carlo's MCP server):

• analyze_storage_costs -- runs the full analysis pipeline and returns pre-formatted output
• get_asset_lineage -- used only for follow-up lineage checks

The analyze_storage_costs tool supports Snowflake, BigQuery, Redshift, and Databricks warehouses only. Other warehouse types are out of scope.

Workflow

Important: These steps are internal instructions for you. Do NOT expose step numbers, step names, or the procedural structure to the user. Just act naturally.

Step 1: Identify the warehouse

You need a warehouse to proceed.

• If the user specified a warehouse (by name or UUID), use it.
• If not: call analyze_storage_costs with no warehouse_id. The tool will either auto-pick when only one supported warehouse exists, or return a list of supported warehouses — let the user choose one, then call the tool again with the chosen warehouse_id.

Step 2: Run the analysis

Call analyze_storage_costs with:

• warehouse_id: the warehouse UUID

The tool fetches candidates, classifies them into waste patterns (Unread, Write-only, Dead-end, Static waste, Zombie, Other stale) and table categories (Temporary, Archive/Snapshot, Production, Other), computes safety tiers, and returns a formatted analysis.

• If the tool returns an error, report it to the user and stop.
• If no candidates are found, tell the user and stop.

Step 3: Present the initial summary

The tool output contains two regions:

1. A <!-- PRESENT_AS_IS --> block with a condensed summary, a Top-N table, and a drill-down prompt.
2. A <!-- CATEGORY_DETAILS --> block with per-category tables wrapped in <!-- CATEGORY:<key> --> markers. Do NOT present these yet.

Present ONLY the <!-- PRESENT_AS_IS --> block — copy it verbatim, preserving every column, row, and value. Add a brief intro sentence if needed, then paste the block unchanged. The user will see the summary and top tables, then choose a category to drill into.

CRITICAL — do NOT call any other tool after analyze_storage_costs succeeds. No search, no get_table, no troubleshooting agents, no cross-checks. The analysis result IS the final answer; your only remaining job is to present the <!-- PRESENT_AS_IS --> block verbatim.

CRITICAL — preserve markdown-linked MCONs verbatim. The pre-formatted tables already contain properly linked MCONs (e.g., [`db:schema.table`](https://getmontecarlo.com/assets/MCON++...)). Never output bare MCON strings as plain text.