Find test files and test functions that cover a given symbol or file. Use instead of Glob/Grep — understands test-to-source mapping, not just filename conventions. When symbol_id (or fqn) is provided, narrows file-level reachability to test files that actually exercise the symbol — graph-resolved...
AI agents call get_tests_for to retrieve information from Trace without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a query operation that retrieves test coverage data from the codebase dependency graph. It has no side effects, cannot modify or delete data, and does not execute code. The 'Read-only' designation in the description confirms the absence of write or execute capabilities.
From the tool's definition Tool description explicitly states 'Read-only' and 'Find test files and test functions that cover a given symbol or file.' The tool retrieves test coverage information without modifying, deleting, or executing code.
Documented attack patterns abuse exactly the kind of access get_tests_for gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Trace, and nothing reaches the server without passing your rules. This is the rule we recommend for get_tests_for:
{
"version": "1",
"default": "deny",
"tools": {
"get_tests_for": {}
}
}get_tests_for is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Find test files and test functions that cover a given symbol or file. Use instead of Glob/Grep — understands test-to-source mapping, not just filename conventions. When symbol_id (or fqn) is provided, narrows file-level reachability to test files that actually exercise the symbol — graph-resolved calls (direct_invocation), import + textual reference (import_and_call), or bare textual mention (text_match). Default min_confidence is import_and_call. For project-wide test coverage gaps use get_untested_symbols instead. Read-only. Returns JSON: { tests: [{ test_file, symbol_id, test_name, line, edge_type, confidence }], total, symbol_filtered?, fell_back_to_file_level? }. It is categorised as a Read tool in the Trace MCP Server, which means it retrieves data without modifying state.
Register the Trace MCP server in PolicyLayer and add a rule for get_tests_for: 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 Trace. Nothing to install.
get_tests_for 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 get_tests_for 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 get_tests_for. 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.
get_tests_for is provided by the Trace MCP server (nikolai-vysotskyi/trace-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 178 Trace tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
178 Trace tools catalogued and risk-classified — across an index of 42,500+ MCP servers.