Retrieve a list of Amazon RDS database instances in a specified AWS region.
[SAFE] List RDS instances
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "aws_rds_instances"
}
}| Name | Required | Description | Default |
|---|---|---|---|
| region | No |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations exist, so the description carries full burden. While '[SAFE]' hints at read-only, it omits details on permissions, rate limits, or error states. The behavioral disclosure is insufficient for a tool without structured annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is very concise (one line), but this comes at the cost of necessary detail. While front-loaded, it barely meets the minimum standard for a useful tool description.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
Given the simple input schema, lack of output schema, and no annotations, the description is critically incomplete. It fails to explain what the tool returns, how to use the optional region, or any typical usage context.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The description does not explain the 'region' parameter at all. With 0% schema description coverage, the agent gains no additional meaning beyond the bare schema.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description explicitly states 'List RDS instances', which is a clear verb+resource combination. It effectively distinguishes from sibling tools like aws_ec2_instances or aws_lambda_functions.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance is provided on when to use this tool versus alternatives, nor any conditions or prerequisites. The description lacks contextual signals for appropriate usage.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.