AI agents invoke run_tests to trigger actions in MCP Prompts Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
The tool executes external code (tests) with automatic framework detection, which means it can run arbitrary test suites whose behavior depends on test file contents. This is inherently an Execute operation. Severity is high because malicious test files could perform unauthorized actions (file I/O, network calls, system commands) under the process context.
From the tool's definition Tool name 'run_tests' combined with description 'Execute tests with automatic framework detection' indicates execution of code via test frameworks.
Documented attack patterns abuse exactly the kind of access run_tests gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP Prompts Server, and nothing reaches the server without passing your rules. This is the rule we recommend for run_tests:
{
"version": "1",
"default": "deny",
"tools": {
"run_tests": {
"limits": [
{
"counter": "run_tests_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}run_tests stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Execute tests with automatic framework detection. It is categorised as a Execute tool in the MCP Prompts Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the MCP Prompts Server MCP server in PolicyLayer and add a rule for run_tests: 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 MCP Prompts Server. Nothing to install.
run_tests is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the run_tests 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 run_tests. 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.
run_tests is provided by the MCP Prompts Server MCP server (sparesparrow/mcp-prompts). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 51 MCP Prompts Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
51 MCP Prompts Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.