AI agents call read_query to retrieve information from AACT Clinical Trials MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
The tool operates on a clinical trials database and returns data without modifying it. The absence of a description is not concerning given the clear naming convention and context of sibling read-only tools. The AACT database is a public, published resource, so unauthorized access risk is minimal. Misuse would involve retrieving trial data, which has no destructive or financial side effects.
From the tool's definition Tool name 'read_query' combined with server description emphasizing 'retrieval and analysis of clinical trial data' with sibling tools like 'fetch_rows', 'get_column_values', 'list_tables', and 'search_columns' that are all unambiguously read-only database…
Documented attack patterns abuse exactly the kind of access read_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and AACT Clinical Trials MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for read_query:
{
"version": "1",
"default": "deny",
"tools": {
"read_query": {}
}
}read_query is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
Free to start. No card required.
read_query. It is categorised as a Read tool in the AACT Clinical Trials MCP Server MCP Server, which means it retrieves data without modifying state.
Register the AACT Clinical Trials MCP Server MCP server in PolicyLayer and add a rule for read_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 AACT Clinical Trials MCP Server. Nothing to install.
read_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 read_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 read_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.
read_query is provided by the AACT Clinical Trials MCP Server MCP server (navisbio/aact_clinicaltrials_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from AACT Clinical Trials MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
7 AACT Clinical Trials MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.