AWS MCP Server

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

Annotations indicate this is a non-destructive, idempotent, open-world operation. The description adds that it updates descriptions specifically for egress rules, which provides some behavioral context beyond annotations. However, it doesn't mention important aspects like authentication requirements, rate limits, or what happens if the rule doesn't exist, leaving gaps in behavioral understanding.

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 function without unnecessary words. It's appropriately sized for a tool with this complexity and gets straight to the point.

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 mutation tool with complex nested parameters (SecurityGroupArgs with multiple sub-properties), no output schema, and only 50% schema coverage, the description is inadequate. It doesn't explain what the tool returns, how to structure the SecurityGroupArgs object, or provide examples, leaving significant gaps for proper tool invocation.

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 50% schema description coverage, the description doesn't compensate for the coverage gap. It mentions 'region' and implies 'SecurityGroupArgs' through context, but adds no meaningful parameter semantics beyond what's already in the schema. The baseline is appropriate given the partial schema documentation.

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 ('Update the description') and target resource ('security group rule egress'), making the purpose understandable. However, it doesn't differentiate from its sibling 'update-security-group-rule-descriptions-ingress' beyond the directional term 'egress', which might not be sufficient for an agent to distinguish between inbound and outbound rule updates without additional context.

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 minimal guidance by specifying 'in the given region', but offers no explicit when-to-use advice, prerequisites, or alternatives. Given the sibling tool 'update-security-group-rule-descriptions-ingress', it fails to clarify when to choose egress over ingress updates, leaving the agent without proper usage context.

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