Upload evidence or documentation for a payment or escrow (works for both fiat and web3 escrows).
Part of the Kustodia Escrow server.
Free to start. No card required.
AI agents use upload_evidence to create or modify resources in Kustodia Escrow. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call upload_evidence repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach Kustodia Escrow.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"upload_evidence": {
"limits": [
{
"counter": "upload_evidence_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full Kustodia Escrow policy for all 36 tools.
These attack patterns abuse exactly the kind of access upload_evidence gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Upload evidence or documentation for a payment or escrow (works for both fiat and web3 escrows).. It is categorised as a Write tool in the Kustodia Escrow MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Kustodia Escrow MCP server in PolicyLayer and add a rule for upload_evidence: 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 Kustodia Escrow. Nothing to install.
upload_evidence 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 upload_evidence 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 upload_evidence. 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.
upload_evidence is provided by the Kustodia Escrow MCP server (kustodia/escrow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 36 Kustodia Escrow tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.