AWS MCP Server

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

Annotations indicate this is a non-readOnly, non-destructive, non-idempotent, open-world operation. The description adds minimal behavioral context beyond this, as it doesn't mention side effects, permissions, or rate limits. However, it doesn't contradict the annotations, so it meets the baseline for adding some value (the region constraint) without rich disclosure.

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 a single, efficient sentence that directly states the tool's purpose without unnecessary words. It is appropriately sized and front-loaded, making it easy to parse quickly.

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?

For a creation tool with no output schema, low schema coverage, and annotations that only cover basic hints, the description is insufficient. It lacks details on required inputs (e.g., VpcId), behavioral traits like idempotency or error handling, and expected outcomes, leaving significant gaps for an AI agent.

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?

Schema description coverage is 50%, with the 'region' parameter well-documented but 'SecurityGroupArgs' nested object only partially described. The description adds no parameter-specific details beyond implying a 'region' input, failing to compensate for the coverage gap. Baseline 3 is appropriate as the schema does some heavy lifting.

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 clearly states the action ('Create') and resource ('security group'), with the additional context of 'in the given region' specifying scope. It distinguishes from sibling tools like 'delete-security-group' or 'list-security-groups' by the verb, though it doesn't explicitly contrast with similar creation tools like 'create-vpc' or 'create-subnet'.

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. The description lacks context about prerequisites (e.g., needing a VPC), exclusions, or comparisons to other tools like 'modify-security-group-rules' or 'update-security-group-rule-descriptions-egress' for related operations.

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