Retrieve account usage limits. Requires an account-level API key.
AI agents call mailosaur_usage_limits to retrieve information from Mailosaur MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves account metadata (usage limits) and has no side effects. It is a straightforward data retrieval operation that does not create, modify, delete, execute code, or commit financial actions. The requirement for an account-level API key reflects authentication, not severity.
From the tool's definition Tool name 'mailosaur_usage_limits' and description 'Retrieve account usage limits' indicate a read-only query operation that retrieves account information without modifying any state.
Attacks that exploit this kind of access
Retrieve account usage limits. Requires an account-level API key. It is categorised as a Read tool in the Mailosaur MCP MCP Server, which means it retrieves data without modifying state.
Register the Mailosaur MCP server in PolicyLayer and add a rule for mailosaur_usage_limits: 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 Mailosaur MCP. Nothing to install.
mailosaur_usage_limits 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 mailosaur_usage_limits 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 mailosaur_usage_limits. 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.
mailosaur_usage_limits is provided by the Mailosaur MCP server (mrnewdelhi/mailosaur-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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