Register and connect a new downstream MCP server while SINT is running. Use this to aggregate a new stdio server into the proxy without restarting the process; on success the server is immediately available through the aggregated tool namespace. Returns a confirmation message including the discov...
AI agents use sint__add_server to create or update resources in SINT Protocol — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your SINT Protocol environment.
The tool creates or modifies the proxy's server registry by adding a new downstream MCP server dynamically. This is a Write operation because it reversibly adds a new data entry (server registration) to the SINT proxy's configuration.
From the tool's definition Tool description states it 'Register and connect a new downstream MCP server' and makes the server 'immediately available through the aggregated tool namespace'. This creates a new configuration entry and modifies the active proxy state.
Documented attack patterns abuse exactly the kind of access sint__add_server gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and SINT Protocol, and nothing reaches the server without passing your rules. This is the rule we recommend for sint__add_server:
{
"version": "1",
"default": "deny",
"tools": {
"sint__add_server": {
"limits": [
{
"counter": "sint__add_server_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}sint__add_server 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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Register and connect a new downstream MCP server while SINT is running. Use this to aggregate a new stdio server into the proxy without restarting the process; on success the server is immediately available through the aggregated tool namespace. Returns a confirmation message including the discovered tool count, or an error message if connection fails. It is categorised as a Write tool in the SINT Protocol MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the SINT Protocol MCP server in PolicyLayer and add a rule for sint__add_server: 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 SINT Protocol. Nothing to install.
sint__add_server 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 sint__add_server 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 sint__add_server. 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.
sint__add_server is provided by the SINT Protocol MCP server (sint-ai/sint-protocol). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from SINT Protocol, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
21 SINT Protocol tools catalogued and risk-classified — across an index of 43,000+ MCP servers.