Get stdout/stderr output around the current focus position. Output is scoped to the current process — use goto to navigate to a content process first if needed. Results include event IDs for navigation.
AI agents call stdout_stderr to retrieve information from Pernosco without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves program output (stdout/stderr) from a debugging trace without modifying state, executing code, or affecting the debugged process. It is purely informational and read-only in nature, appropriate for inspecting past execution artifacts during debugging sessions.
From the tool's definition Tool description states 'Get stdout/stderr output' — a retrieval operation with 'no side effects'. The tool 'includes event IDs for navigation' but does not modify, execute, or delete anything. It reads debugging session data.
Attacks that exploit this kind of access
Get stdout/stderr output around the current focus position. Output is scoped to the current process — use goto to navigate to a content process first if needed. Results include event IDs for navigation. It is categorised as a Read tool in the Pernosco MCP Server, which means it retrieves data without modifying state.
Register the Pernosco MCP server in PolicyLayer and add a rule for stdout_stderr: 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 Pernosco. Nothing to install.
stdout_stderr 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 stdout_stderr 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 stdout_stderr. 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.
stdout_stderr is provided by the Pernosco MCP server (jnjaeschke/pernosco-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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