Expand and rewrite search queries based on an up-to-date query expansion model. This tool takes an initial query and returns multiple expanded queries that can be used for more diversed and deeper searches. Useful for improving deep research results by searching broader and deeper.
AI agents call expand_query to retrieve information from Jina AI without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
query | string | — | The search query to expand (e.g., 'machine learning', 'climate change') |
Parameters from the server's own tool schema.
This is a query transformation and retrieval tool. It reads/analyzes an input query and outputs expanded versions to improve search coverage. No data is created, modified, deleted, or executed—it purely returns computed suggestions.
From the tool's definition expand_query takes an initial query and returns multiple expanded/rewritten queries for search purposes. It retrieves and processes data (query suggestions) without modifying, deleting, or executing operations that would have side effects beyond providing…
Risk signalsAccepts freeform code/query input (query)
Documented attack patterns abuse exactly the kind of access expand_query gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Jina AI, and nothing reaches the server without passing your rules. This is the rule we recommend for expand_query:
{
"version": "1",
"default": "deny",
"tools": {
"expand_query": {}
}
}expand_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.
Expand and rewrite search queries based on an up-to-date query expansion model. This tool takes an initial query and returns multiple expanded queries that can be used for more diversed and deeper searches. Useful for improving deep research results by searching broader and deeper. It is categorised as a Read tool in the Jina AI MCP Server, which means it retrieves data without modifying state.
expand_query accepts 1 parameter: query. The full parameter table on this page comes from the server's own tool schema.
Register the Jina AI MCP server in PolicyLayer and add a rule for expand_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 Jina AI. Nothing to install.
expand_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 expand_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 expand_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.
expand_query is provided by the Jina AI MCP server (jina). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Jina AI, 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.
21 Jina AI tools catalogued and risk-classified — across an index of 43,000+ MCP servers.