Add a test case for regex pattern validation. Each test case consists of an input string and the expected match/output.
AI agents use add_test_case to create or update resources in MCPGex — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCPGex environment.
This tool creates or appends test case data in a reversible manner (test cases can be cleared or updated). It does not execute code, delete data irreversibly, move money, or trigger external operations. The blast radius is minimal — adding benign test data poses negligible risk even if misused by an agent.
From the tool's definition Tool description states 'Add a test case' — a create operation that modifies the test case collection. No deletion or system execution occurs.
Documented attack patterns abuse exactly the kind of access add_test_case gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCPGex, and nothing reaches the server without passing your rules. This is the rule we recommend for add_test_case:
{
"version": "1",
"default": "deny",
"tools": {
"add_test_case": {
"limits": [
{
"counter": "add_test_case_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}add_test_case 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.
Free to start. No card required.
Add a test case for regex pattern validation. Each test case consists of an input string and the expected match/output. It is categorised as a Write tool in the MCPGex MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCPGex MCP server in PolicyLayer and add a rule for add_test_case: 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 MCPGex. Nothing to install.
add_test_case 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 add_test_case 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 add_test_case. 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.
add_test_case is provided by the MCPGex MCP server (patzedi/mcpgex). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCPGex, 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.
4 MCPGex tools catalogued and risk-classified — across an index of 43,000+ MCP servers.