Search for works in the Digital Collections using field-based and/or natural language queries. If both a natural language query and specific field values are provided, the natural language query will take priority, using the specified field values as additional constraints. The result will also i...
Risk signalsAccepts freeform code/query input (query) · High parameter count (29 properties)
Part of the Northwestern University Libraries Digital Collections API server.
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AI agents call search to retrieve information from Northwestern University Libraries Digital Collections API 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 search 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": {
"search": {}
}
}See the full Northwestern University Libraries Digital Collections API policy for all 8 tools.
These attack patterns abuse exactly the kind of access search 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.
Search for works in the Digital Collections using field-based and/or natural language queries. If both a natural language query and specific field values are provided, the natural language query will take priority, using the specified field values as additional constraints. The result will also include a list of aggregations that show how many results match different values for certain fields. For example, you could see how many results match each collection, work type, or visibility and use that information to refine your search. Perform an empty search to retrieve all works and their aggregations. NOTE: Structured field values enclosed in double quotes will be treated as exact, case-sensitive matches, while unquoted values will be treated as full-text searches.. It is categorised as a Read tool in the Northwestern University Libraries Digital Collections API MCP Server, which means it retrieves data without modifying state.
Register the Northwestern University Libraries Digital Collections API MCP server in PolicyLayer and add a rule for search: 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 Northwestern University Libraries Digital Collections API. Nothing to install.
search 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 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. 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 is provided by the Northwestern University Libraries Digital Collections API MCP server (@nulib/dc-api-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 8 Northwestern University Libraries Digital Collections API tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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