Gets the size of the collection.
AI agents call collection_storage_size to retrieve information from Legacy Mongodb without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves metadata about a collection's storage size without modifying data, executing code, or triggering external operations. It has minimal blast radius—an AI agent calling this tool cannot cause data loss, execute arbitrary operations, or modify state. Classification as Read is appropriate for information-retrieval operations on databases.
From the tool's definition Tool name is 'collection_storage_size' and description states it 'Gets the size of the collection.' This is a retrieval operation with no modification or execution capability.
Attacks that exploit this kind of access
Gets the size of the collection. It is categorised as a Read tool in the Legacy Mongodb MCP Server, which means it retrieves data without modifying state.
Register the Legacy Mongodb MCP server in PolicyLayer and add a rule for collection_storage_size: 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 Legacy Mongodb. Nothing to install.
collection_storage_size 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 collection_storage_size 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 collection_storage_size. 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.
collection_storage_size is provided by the Legacy Mongodb MCP server (webxspark/legacy-mongodb-mcp). 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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