AWS MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It successfully communicates the mandatory regional constraint for CloudFront scope (us-east-1 requirement) which is not visible in the schema, though it omits explicit read-only classification.

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?

Two efficient sentences with zero waste: the first establishes the operation, the second provides essential scope constraints. Information is front-loaded and 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?

Given the 4-parameter input with full schema coverage and no output schema, the description adequately covers the primary complexity (scope selection) and critical AWS-specific constraint (us-east-1 for CloudFront). Complete enough for invocation decisions.

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?

Despite 100% schema coverage (baseline 3), the description adds significant semantic value by specifying the us-east-1 regional requirement for CLOUDFRONT scope and adding 'AppSync' to the list of supported resources, neither of which are in the schema's scope description.

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 explicitly states the action ('List') and resource ('WAF v2 Web ACLs'), clearly distinguishing it from sibling tools like 'aws_wafv2_get_web_acl' (specific retrieval) and 'aws_wafv2_list_ip_sets' (different resource type).

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 clear guidance on the critical 'scope' parameter values, explaining REGIONAL covers ALB/API GW/AppSync while CLOUDFRONT requires us-east-1. Lacks explicit guidance on when to choose this over the 'get_web_acl' sibling, but the scope constraints offer strong usage context.

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