Evaluate a single Outcome Contract assertion against caller-supplied
AI agents call oc_assert to retrieve information from OpenChrome without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs validation or assertion logic—checking whether a condition or contract is met. Assertions are typically read-only operations that evaluate state without modifying it. No side effects, no data creation, modification, or deletion mentioned. The operation is informational in nature, similar to a query or check.
From the tool's definition Tool name 'oc_assert' with description 'Evaluate a single Outcome Contract assertion against caller-supplied' indicates an evaluation/assertion operation.
Documented attack patterns abuse exactly the kind of access oc_assert gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and OpenChrome, and nothing reaches the server without passing your rules. This is the rule we recommend for oc_assert:
{
"version": "1",
"default": "deny",
"tools": {
"oc_assert": {}
}
}oc_assert is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Evaluate a single Outcome Contract assertion against caller-supplied. It is categorised as a Read tool in the OpenChrome MCP Server, which means it retrieves data without modifying state.
Register the OpenChrome MCP server in PolicyLayer and add a rule for oc_assert: 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 OpenChrome. Nothing to install.
oc_assert 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 oc_assert 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 oc_assert. 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.
oc_assert is provided by the OpenChrome MCP server (shaun0927/openchrome). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 106 OpenChrome tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
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106 OpenChrome tools catalogued and risk-classified — across an index of 42,500+ MCP servers.