Query past variable values from the session recorder (time-travel debugging). WHEN TO USE: - To see how a variable changed over execution steps - To compare values between steps without re-running - To understand state progression leading to a bug DOES NOT REQUIRE PAUSED STATE - can query history...
AI agents call query_history to retrieve information from Smart Xdebug without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a Read operation—it retrieves historical debugging information for inspection purposes only. There are no side effects, no data modification, and no irreversible actions. The tool cannot execute code, delete data, or affect the application state; it only provides visibility into past variable states during debugging.
From the tool's definition The tool queries and retrieves historical variable values from a session recorder without modifying any data.
Attacks that exploit this kind of access
Query past variable values from the session recorder (time-travel debugging). WHEN TO USE: - To see how a variable changed over execution steps - To compare values between steps without re-running - To understand state progression leading to a bug DOES NOT REQUIRE PAUSED STATE - can query history anytime during an active session. RETURNS: Array of historical values with step numbers and timestamps, showing how the variable changed over time. LIMITATION: Only variables that were inspected via inspect_variable are recorded. If you didn. It is categorised as a Read tool in the Smart Xdebug MCP Server, which means it retrieves data without modifying state.
Register the Smart Xdebug MCP server in PolicyLayer and add a rule for query_history: 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 Smart Xdebug. Nothing to install.
query_history 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 query_history 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 query_history. 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.
query_history is provided by the Smart Xdebug MCP server (wallter/smart-xdebug-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
query_history is one line of Smart Xdebug's registry record.
The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.
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