fw_media_prune
Manually trigger a prune of cached remote audio files older than N days. Default retention is 14 days (7 days on Pi-class hosts). Rate-limited: 2/hour.
This record as markdown: /tools/kh0pper-crow/fw-media-prune.md
What fw_media_prune does on Crow
AI agents call fw_media_prune to permanently remove resources in Crow, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why fw_media_prune is rated Critical
This tool permanently deletes cached remote audio files based on age. File deletion/pruning is irreversible (Destructive category). The blast radius is high because misconfiguring the retention period (e.g., setting N=0 or a very large value) could wipe all cached media files with no recovery path. The rate limit of 2/hour suggests the developers recognize its destructive potential.
From the tool's definition 'prune of cached remote audio files older than N days' — pruning/deleting cached files is irreversible deletion of stored data
Attacks that exploit this kind of access
The rule that runs fw_media_prune safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Crow, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For fw_media_prune, this is the rule to start with:
fw_media_prune is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Crow, apply this rule, and every fw_media_prune call is checked against it from then on.
Questions about fw_media_prune
Manually trigger a prune of cached remote audio files older than N days. Default retention is 14 days (7 days on Pi-class hosts). Rate-limited: 2/hour. It is categorised as a Destructive tool in the Crow MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Crow MCP server in PolicyLayer and add a rule for fw_media_prune: 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 Crow. Nothing to install.
fw_media_prune is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the fw_media_prune 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 fw_media_prune. 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.
fw_media_prune is provided by the Crow MCP server (kh0pper/crow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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