Search for schemas in a registry using keywords. REQUIREMENTS: - You MUST use this tool to find schemas for AWS service events - You MUST search in the "aws.events" registry for AWS service events - You MUST use this tool when implementing Lambda functions that consume events from EventBridge - ...
Part of the AWS Serverless MCP Server MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.
AI agents call search_schema to retrieve information from AWS Serverless MCP Server without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though search_schema only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
tools:
search_schema:
rules:
- action: allowSee the full AWS Serverless MCP Server policy for all 32 tools.
Agents calling read-class tools like search_schema have been implicated in these attack patterns. Read the full case and prevention policy for each:
Other tools in the Read risk category across the catalogue. The same policy patterns (rate-limit, allow) apply to each.
Search for schemas in a registry using keywords. REQUIREMENTS: - You MUST use this tool to find schemas for AWS service events - You MUST search in the "aws.events" registry for AWS service events - You MUST use this tool when implementing Lambda functions that consume events from EventBridge - You SHOULD prefix search keywords with "aws." for optimal results (e.g., "aws.s3", "aws.ec2") - You MAY filter results using additional keywords for specific event types USE CASES: 1. Lambda Function Development with EventBridge: - CRITICAL: Required for Lambda functions consuming events from EventBridge - Search for event schemas your function needs to process - Example: "aws.s3" for S3 events, "aws.dynamodb" for DynamoDB streams - Use results with describe_schema to get complete event structure 2. EventBridge Rule Creation: - Find schemas to create properly structured event patterns - Example: "aws.ec2" for EC2 instance state changes - Ensure exact field names and types in rule patterns IMPLEMENTATION FLOW: 1. Search aws.events registry for service schemas 2. Note relevant schema names from results 3. Use describe_schema to get complete definitions 4. Implement handlers using exact schema structure. It is categorised as a Read tool in the AWS Serverless MCP Server MCP Server, which means it retrieves data without modifying state.
Add a rule in your Intercept YAML policy under the tools section for search_schema. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the AWS Serverless MCP Server MCP server.
search_schema 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 search_schema rule in your Intercept 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 Intercept policy for search_schema. 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.
search_schema is provided by the AWS Serverless MCP Server MCP server (awslabs.aws-serverless-mcp-server). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic policy on every MCP tool call. Per-identity grants. Full audit log.