Add a member to a Redis sorted set with an optional expiration time. Args: key (str): The sorted set key. score (float): The score of the member. member (str): The member to add. expiration (int, optional): Expiration time in seconds. Returns: str: Confirmation message or an error message.
AI agents use zadd to create or update resources in Redis MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Redis MCP Server environment.
zadd modifies data by adding or updating a member in a sorted set, which is reversible (the member can be removed later via del or zrem). It does not delete data irreversibly, execute arbitrary code, or move financial assets. While it does modify state, the operation is not destructive.
From the tool's definition Tool description explicitly states 'Add a member to a Redis sorted set' and accepts parameters for key, score, member, and optional expiration. This is a create/modify operation that changes data in Redis.
Documented attack patterns abuse exactly the kind of access zadd gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Redis MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for zadd:
{
"version": "1",
"default": "deny",
"tools": {
"zadd": {
"limits": [
{
"counter": "zadd_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}zadd 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.
Free to start. No card required.
Add a member to a Redis sorted set with an optional expiration time. Args: key (str): The sorted set key. score (float): The score of the member. member (str): The member to add. expiration (int, optional): Expiration time in seconds. Returns: str: Confirmation message or an error message. It is categorised as a Write tool in the Redis MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Redis MCP Server MCP server in PolicyLayer and add a rule for zadd: 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 Redis MCP Server. Nothing to install.
zadd 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 zadd 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 zadd. 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.
zadd is provided by the Redis MCP Server MCP server (redis/mcp-redis). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 53 Redis MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
53 Redis MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.