Get organized list of available fields for customizing search results. This tool provides a list of available fields that can be used to customize the results of other search tools. The fields are organized into categories. Input: - `category`: An optional string to specify a category of fiel...
Part of the Clinical Trials Data Server MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents call get_available_fields to retrieve information from Clinical Trials Data Server 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 get_available_fields 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.
tools:
get_available_fields:
rules:
- action: allowSee the full Clinical Trials Data Server policy for all 12 tools.
Agents calling read-class tools like get_available_fields have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.
Get organized list of available fields for customizing search results. This tool provides a list of available fields that can be used to customize the results of other search tools. The fields are organized into categories. Input: - `category`: An optional string to specify a category of fields to return. If not provided, all categories and default fields will be returned. Example: `'conditions'`. It is categorised as a Read tool in the Clinical Trials Data Server MCP Server, which means it retrieves data without modifying state.
Add a rule in your Intercept YAML policy under the tools section for get_available_fields. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Clinical Trials Data Server MCP server.
get_available_fields 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 get_available_fields rule in your Intercept 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 Intercept policy for get_available_fields. 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.
get_available_fields is provided by the Clinical Trials Data Server MCP server (plainyogurt21/clintrials-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Open source. One binary. Zero dependencies.
npx -y @policylayer/intercept