Check whether the locally cached source file for a citation is still current. Issues a conditional HEAD request using the stored ETag/Last-Modified. If the remote source is newer, downloads and updates the local copy automatically.
AI agents use check_source_freshness to create or update resources in AusLaw MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your AusLaw MCP environment.
The tool performs a read-like check (HEAD request) but its side effect is automatically downloading and updating the local cached copy when a newer version is found. This constitutes a reversible write/update operation on local storage, making Write the appropriate category.
From the tool's definition If the remote source is newer, downloads and updates the local copy automatically
Documented attack patterns abuse exactly the kind of access check_source_freshness gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and AusLaw MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for check_source_freshness:
{
"version": "1",
"default": "deny",
"tools": {
"check_source_freshness": {
"limits": [
{
"counter": "check_source_freshness_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}check_source_freshness stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
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Check whether the locally cached source file for a citation is still current. Issues a conditional HEAD request using the stored ETag/Last-Modified. If the remote source is newer, downloads and updates the local copy automatically. It is categorised as a Write tool in the AusLaw MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the AusLaw MCP server in PolicyLayer and add a rule for check_source_freshness: 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 AusLaw MCP. Nothing to install.
check_source_freshness is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the check_source_freshness 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 check_source_freshness. 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.
check_source_freshness is provided by the AusLaw MCP server (russellbrenner/auslaw-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from AusLaw MCP, 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.
18 AusLaw MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.