Real-time US river levels — gage height (ft) + streamflow/discharge (ft3/s) from USGS NWIS (keyless). Use for "how high / how fast is river X right now", flood risk (rising gage) or drought (low flow). Provide a 2-letter US state, USGS site number(s) comma-separated, or neither for major rivers. ...
Part of the Dynamic Feed server.
Free to start. No card required.
AI agents call water_levels to retrieve information from Dynamic Feed 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 water_levels 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": {
"water_levels": {}
}
}See the full Dynamic Feed policy for all 50 tools.
These attack patterns abuse exactly the kind of access water_levels 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.
Real-time US river levels — gage height (ft) + streamflow/discharge (ft3/s) from USGS NWIS (keyless). Use for "how high / how fast is river X right now", flood risk (rising gage) or drought (low flow). Provide a 2-letter US state, USGS site number(s) comma-separated, or neither for major rivers. Args: state: 2-letter US state code (e.g. TX, CA). site: USGS site number(s), comma-separated. limit: max sites.. It is categorised as a Read tool in the Dynamic Feed MCP Server, which means it retrieves data without modifying state.
Register the Dynamic Feed MCP server in PolicyLayer and add a rule for water_levels: 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 Dynamic Feed. Nothing to install.
water_levels 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 water_levels 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 water_levels. 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.
water_levels is provided by the Dynamic Feed MCP server (https://dynamicfeed.ai/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 50 Dynamic Feed tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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