AI agents use send_gmail to create or update resources in Gmail MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Gmail MCP Server environment.
Sending emails creates new data in Gmail accounts and can reach external recipients. While emails can technically be deleted/unsent (depending on Gmail's undo window), the primary action is data creation. This is Write rather than Execute because the tool's core function is to create email objects with user-supplied content, not to execute arbitrary code or perform conditional logic.
From the tool's definition Tool name 'send_gmail' combined with description 'Send an email with optional attachments' indicates creation of new email messages. This is a reversible write operation that modifies email state by adding new messages.
Documented attack patterns abuse exactly the kind of access send_gmail gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Gmail MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for send_gmail:
{
"version": "1",
"default": "deny",
"tools": {
"send_gmail": {
"limits": [
{
"counter": "send_gmail_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}send_gmail stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Send an email with optional attachments. It is categorised as a Write tool in the Gmail MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Gmail MCP Server MCP server in PolicyLayer and add a rule for send_gmail: 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 Gmail MCP Server. Nothing to install.
send_gmail is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the send_gmail 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 send_gmail. 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.
send_gmail is provided by the Gmail MCP Server MCP server (quantum-369/gmail-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Gmail MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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4 Gmail MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.