AWS MCP Server

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

No annotations provided, so description must carry full behavioral burden. Discloses the filtering capability (by attached VPC) but omits explicit read-only assurance, pagination behavior, or required AWS permissions. 'Describe' implies read-only but doesn't confirm safety explicitly.

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?

Extremely concise single sentence (7 words) with zero waste. Front-loaded with verb and resource, filtering clause follows naturally. Every word earns its place.

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?

Adequate for a simple 3-parameter describe operation with full schema coverage. Lacking output schema, description could mention read-only nature or typical use cases (e.g., finding IGWs for VPC connectivity). Sufficient but minimal.

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 100% (all 3 parameters well-documented). Description mentions 'attached VPC' which aligns with vpc_id parameter semantics, but adds no syntax details, validation rules, or examples beyond what the schema already provides. Baseline score for high 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?

Clear verb ('Describe') and specific resource ('internet gateways') that distinguishes from sibling tools like aws_vpc_describe_nat_gateways or aws_vpc_describe_vpcs. However, 'Describe' relies on AWS API familiarity without explaining what information is returned.

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?

Provides implied usage by mentioning the optional VPC filter ('optionally filtered by attached VPC'), which hints at when to use the vpc_id parameter. Lacks explicit when-not guidance or references to related tools like aws_vpc_describe_vpcs for VPC-level details.

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