AWS MCP Server

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

Annotations provide good coverage (readOnlyHint=false, destructiveHint=false, idempotentHint=true, openWorldHint=true), so the description doesn't need to repeat these. However, it adds minimal behavioral context beyond annotations—it clarifies the three possible association targets but doesn't explain implications like routing changes or conflicts.

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 and resources. There's no wasted verbiage or redundancy, 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?

Given the tool's moderate complexity (mutation with nested parameters, no output schema), the description is adequate but incomplete. It covers the basic purpose but lacks usage guidelines, detailed parameter semantics, and behavioral nuances (e.g., idempotency effects, error conditions), leaving the agent to rely heavily on annotations and schema.

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% (only 'region' and 'DryRun' have descriptions; nested object properties lack them). The description mentions 'subnet or internet gateway or virtual private gateway', which hints at GatewayId and SubnetId usage, but doesn't clarify their mutual exclusivity or provide format examples. This partially compensates but leaves gaps.

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 ('associate') and the resources involved ('route table with a subnet or internet gateway or virtual private gateway'), making the purpose unambiguous. However, it doesn't explicitly differentiate from its sibling 'disassociate-route-table' or 'replace-route-table-association', which would be needed for a perfect score.

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 no guidance on when to use this tool versus alternatives like 'disassociate-route-table' or 'replace-route-table-association'. It also doesn't mention prerequisites (e.g., needing existing route tables and targets) or constraints (e.g., one route table per subnet).

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