AWS MCP Server

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

Annotations provide readOnlyHint=true, destructiveHint=false, openWorldHint=true, and idempotentHint=true, covering safety and idempotency. The description adds no behavioral traits beyond this, such as pagination details (implied by NextToken/MaxResults in schema) or permission requirements. It doesn't contradict annotations, but offers minimal extra context.

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 front-loads the core action ('List all security group rules') without unnecessary words. It's appropriately sized for a listing tool, with no wasted space or redundancy.

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 tool's complexity (2 parameters, nested objects, no output schema) and rich annotations, the description is minimal but functional. It states what the tool does, but lacks details on usage, parameter interplay, or output format, which could aid an agent in selecting and invoking it correctly. It's adequate but leaves 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?

Schema description coverage is 50%, with parameters like 'region' and 'SecurityGroupRuleArgs' documented in the schema. The description mentions 'given region' but doesn't elaborate on parameter usage, such as filtering with SecurityGroupRuleArgs or pagination. It adds little beyond the schema, but the baseline is 3 due to moderate schema coverage.

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 ('List all') and resource ('security group rules') with regional scope ('in the given region'), making the purpose evident. However, it doesn't differentiate from sibling tools like 'list-security-groups' or 'modify-security-group-rules', which would require mentioning this is specifically for rules within groups rather than groups themselves or modification operations.

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. For example, it doesn't mention that this is for listing rules within security groups, as opposed to 'list-security-groups' for listing groups themselves or 'modify-security-group-rules' for changes. The description lacks context about prerequisites or typical use cases.

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