AWS MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not indicate that this is a read-only operation, mention pagination behavior (how max_results interacts with AWS's native pagination), or describe the return format since no output schema exists.

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 extremely concise at seven words. While efficient and front-loaded, it errs on the side of under-specification given the tool's complexity (5 parameters, no output schema, no annotations). It wastes no words but leaves critical context unstated.

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?

Despite having complete input schema coverage, the description is inadequate for a tool with five parameters and no annotations or output schema. It omits what data is returned (execution ARNs, names, statuses, timestamps?), pagination tokens, and error conditions. For an AWS list operation, this minimal description leaves significant gaps.

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?

With 100% schema description coverage, the structured schema already documents all five parameters including the enum values for status_filter and the default for max_results. The description adds no semantic information beyond what the schema provides, earning the baseline score for high-coverage schemas.

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 states a clear verb ('List') and resource ('executions for a Step Functions state machine'), but it fails to distinguish from sibling tools like aws_sfn_describe_execution (which retrieves a specific execution by ARN) or aws_sfn_list_state_machines (which lists state machines, not executions). It does not clarify that this tool requires a state_machine_arn to scope the query.

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?

The description provides no guidance on when to use this tool versus alternatives. It does not mention the prerequisite workflow (typically obtaining state_machine_arn from aws_sfn_list_state_machines first) or when to use aws_sfn_describe_execution for detailed single-execution lookup instead.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.