AI agents call analyze_null_patterns to retrieve information from Mssql without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
schema | string | — | Schema name (default: dbo) |
connectionName | string | — | Named connection to use (e.g., 'production', 'staging') |
connectionString | string | — | SQL Server connection string (uses default if not provided) |
minNullPercentage | number | — | Minimum null percentage to include (default: 10) |
Parameters from the server's own tool schema.
This tool queries database metadata and statistics to identify null patterns. It does not create, modify, delete, or execute operations with side effects. It is analogous to other sibling analysis tools (analyze_table_stats, analyze_index_usage) that inspect database state without mutation.
From the tool's definition Tool performs analysis and retrieval of null patterns in columns without modifying data. Description states 'Find columns with high null percentages and analyze null patterns' — purely informational operations.
Attacks that exploit this kind of access
Find columns with high null percentages and analyze null patterns. It is categorised as a Read tool in the Mssql MCP Server, which means it retrieves data without modifying state.
analyze_null_patterns accepts 4 parameters: schema, connectionName, connectionString, minNullPercentage. The full parameter table on this page comes from the server's own tool schema.
Register the Mssql MCP server in PolicyLayer and add a rule for analyze_null_patterns: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Mssql. Nothing to install.
analyze_null_patterns is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the analyze_null_patterns rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for analyze_null_patterns. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
analyze_null_patterns is provided by the Mssql MCP server (mssql-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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