AWS MCP Server

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

Annotations provide key behavioral hints: readOnlyHint=false (mutation), destructiveHint=false (safe), openWorldHint=true (supports custom parameters), and idempotentHint=false (non-idempotent). The description adds minimal context beyond this, stating it creates a new gateway but not elaborating on side effects, permissions, or AWS-specific behaviors like eventual consistency. No contradiction with annotations 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 a single, efficient sentence that front-loads the core action without unnecessary words. It earns its place by clearly stating the tool's primary function, 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 mutation tool with no output schema, low schema coverage (50%), and complex nested parameters, the description is inadequate. It doesn't explain what an internet gateway is, how it integrates with AWS services, what the output looks like, or error conditions, leaving significant gaps for an agent to use it effectively.

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 'region' and 'DryRun' well-documented in the schema, but 'TagSpecifications' and its nested properties lack descriptions. The description adds no parameter-specific information beyond implying a region is required, failing to compensate for the coverage gap or explain complex tagging structures.

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 ('internet gateway') with regional context ('in the given region'), making the purpose specific and understandable. However, it doesn't explicitly differentiate from sibling tools like 'attach-internet-gateway' or 'detach-internet-gateway', which would require mentioning this creates a new standalone gateway rather than attaching to a VPC.

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 doesn't mention prerequisites (e.g., needing a VPC to attach it to later), exclusions, or related tools like 'attach-internet-gateway' for making it functional. This leaves the agent without context for appropriate tool selection.

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