AI agents call search_works_by_query to retrieve information from Crossref MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries academic literature metadata from Crossref without side effects. Search operations are inherently Read category—they retrieve data for inspection without creating, modifying, or deleting anything. No financial transactions, code execution, or destructive actions are involved.
From the tool's definition Tool name 'search_works_by_query' indicates a search operation that retrieves academic literature data. Sibling tools (search_journals, search_funders, get_paper_metadata, get_work_metadata) are all Read operations that query the Crossref database without…
Documented attack patterns abuse exactly the kind of access search_works_by_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Crossref MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for search_works_by_query:
{
"version": "1",
"default": "deny",
"tools": {
"search_works_by_query": {}
}
}search_works_by_query is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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search_works_by_query. It is categorised as a Read tool in the Crossref MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Crossref MCP Server MCP server in PolicyLayer and add a rule for search_works_by_query: 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 Crossref MCP Server. Nothing to install.
search_works_by_query 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 search_works_by_query 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 search_works_by_query. 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.
search_works_by_query is provided by the Crossref MCP Server MCP server (jackkuo666/crossref-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Crossref MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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9 Crossref MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.