Autonomous Query Guardrail & Tool-Calling Sanitization Roadmap

Role: Principal Data Security & Agent Safety Engineer specializing in dynamic SQL AST validation pipelines.

Context

• Agent Runtime Environment: {{orchestrator_runtime}}
• Target SQL Flavor: {{sql_flavor}}
• Target Ephemeral Sandbox Schema: {{sandbox_schema}}
• Blocked AST Operators & Functions: {{blocked_ast_nodes}}
• Max Parallel Queries: {{concurrency_limit}}
• Audit Log Destination Table: {{telemetry_table}}

Task

Formulate a production-ready operational plan for an intermediate SQL sanitization and validation pipeline that inspects, rewrites, and sandboxes autonomous agent queries before tool invocation.

Method

1. Establish the query interception hook within {{orchestrator_runtime}} before tool execution occurs.
2. Construct an Abstract Syntax Tree (AST) validation stage tuned to {{sql_flavor}} to parse candidate queries and detect syntax anomalies.
3. Implement blacklist filters that instantly reject queries containing any tokens or nodes specified in {{blocked_ast_nodes}}.
4. Design query transformation rules that inject standard LIMIT clauses, qualify unqualified table names, and reroute writes into {{sandbox_schema}}.
5. Calibrate dynamic cost estimation (EXPLAIN plan evaluation) to reject queries whose estimated cost exceeds safety thresholds.
6. Integrate connection throttling to ensure concurrent tool invocations remain within {{concurrency_limit}}.
7. Implement structured telemetry pipelines persisting validation results, query runtimes, and agent metadata directly to {{telemetry_table}}.

Constraints

• MUST reject queries failing static AST parsing before sending any network request to the database.
• MUST NOT permit direct query execution outside of {{sandbox_schema}} for unverified agent runs.
• Sanitization latency overhead MUST remain under 20 milliseconds per query.
• All query parsing errors MUST return structured, actionable correction hints back to the LLM agent.

Output format

• Phase 1: Middleware Architecture & Parsing Flow (component diagram description and sequence)
• Phase 2: AST Rule Set & Node Interception Logic (explicit mapping of {{blocked_ast_nodes}} handling)
• Phase 3: Sandboxing & Query Transformation Specifications (rewrite rule definitions with before/after examples)
• Phase 4: Telemetry Schema & Logging Protocol (DDL and payload definition for {{telemetry_table}})
• Phase 5: Failure Mode Handling & Feedback Loops (table of error codes, LLM prompts, and retry policies)

Self-review

• Does the plan address SQL dialect quirks specific to {{sql_flavor}}?
• Are all rejected AST nodes from {{blocked_ast_nodes}} explicitly handled with deterministic error codes?
• Does the feedback mechanism provide sufficient semantic detail for the agent to self-heal invalid queries?