Look up multiple legal citations in a single request. This is more efficient than making individual requests for each citation. Accepts up to 100 citations at once. Args: citations: List of citation strings to look up (max 100). ctx: The FastMCP context for logging and accessing shared resources....
Part of the CourtListener server.
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AI agents call citation_batch_lookup_citations to retrieve information from CourtListener without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though citation_batch_lookup_citations only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"citation_batch_lookup_citations": {}
}
}See the full CourtListener policy for all 19 tools.
These attack patterns abuse exactly the kind of access citation_batch_lookup_citations gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Look up multiple legal citations in a single request. This is more efficient than making individual requests for each citation. Accepts up to 100 citations at once. Args: citations: List of citation strings to look up (max 100). ctx: The FastMCP context for logging and accessing shared resources. Returns: dict[str, Any]: A dictionary mapping each citation to its corresponding opinion(s). Raises: ValueError: If COURT_LISTENER_API_KEY is not found in environment variables. httpx.HTTPStatusError: If the API request fails.. It is categorised as a Read tool in the CourtListener MCP Server, which means it retrieves data without modifying state.
Register the CourtListener MCP server in PolicyLayer and add a rule for citation_batch_lookup_citations: 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 CourtListener. Nothing to install.
citation_batch_lookup_citations 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 citation_batch_lookup_citations 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 citation_batch_lookup_citations. 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.
citation_batch_lookup_citations is provided by the CourtListener MCP server (https://courtlistener-mcp.vaquill.ai/mcp/). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 19 CourtListener tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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