Check if the authenticated user is following another user
AI agents call isFollowing to retrieve information from Twitter Client MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves follow-relationship state between users. It performs a query with no side effects, no data modification, no code execution, and no irreversible actions. This is a straightforward read operation typical of social media relationship queries.
From the tool's definition Tool description states 'Check if the authenticated user is following another user' — a query operation that retrieves relationship status without modification or side effects.
Documented attack patterns abuse exactly the kind of access isFollowing gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Twitter Client MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for isFollowing:
{
"version": "1",
"default": "deny",
"tools": {
"isFollowing": {}
}
}isFollowing is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Check if the authenticated user is following another user. It is categorised as a Read tool in the Twitter Client MCP MCP Server, which means it retrieves data without modifying state.
Register the Twitter Client MCP server in PolicyLayer and add a rule for isFollowing: 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 Twitter Client MCP. Nothing to install.
isFollowing 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 isFollowing 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 isFollowing. 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.
isFollowing is provided by the Twitter Client MCP server (mzkrasner/twitter-client-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Twitter Client MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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20 Twitter Client MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.