AI agents call get-posts to retrieve information from Bluesky without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves existing posts without modifying, deleting, or executing any actions. It is a read-only operation that simply fetches data based on provided URIs. The low severity reflects minimal blast radius if misused—an agent could retrieve posts but cannot alter or delete content.
From the tool's definition Tool name 'get-posts' and description 'Get multiple posts by their URIs' indicate a retrieval operation with no side effects.
Documented attack patterns abuse exactly the kind of access get-posts gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Bluesky, and nothing reaches the server without passing your rules. This is the rule we recommend for get-posts:
{
"version": "1",
"default": "deny",
"tools": {
"get-posts": {}
}
}get-posts is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Get multiple posts by their URIs. It is categorised as a Read tool in the Bluesky MCP Server, which means it retrieves data without modifying state.
Register the Bluesky MCP server in PolicyLayer and add a rule for get-posts: 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 Bluesky. Nothing to install.
get-posts 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 get-posts 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 get-posts. 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.
get-posts is provided by the Bluesky MCP server (semioz/bluesky-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Bluesky, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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11 Bluesky tools catalogued and risk-classified — across an index of 43,000+ MCP servers.