AWS MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It fails to indicate what the tool returns (Web ACL object, ARN, or association metadata), error behavior when no Web ACL is attached, or whether this is a read-only operation (though implied by 'Get').

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 with no waste. However, given the complete lack of annotations and output schema, it is slightly too terse—it should include one additional clause about error behavior or return value structure to be fully appropriate for the complexity.

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?

As a getter tool with no output schema and no annotations, the description should explain what happens when the resource has no associated Web ACL. It provides the core purpose and supported resource types but leaves critical operational questions unanswered.

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 100% schema description coverage, the baseline is 3. The description adds value by front-loading the valid resource types (ALB, API GW, AppSync) in the main description text, reinforcing the `resource_arn` parameter constraints even though they are also documented in the schema.

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 uses a specific verb ('Get') and clearly identifies the resource (Web ACL) and scope (associated with an AWS resource). The parenthetical list of supported resource types (ALB, API GW, AppSync) effectively distinguishes this from the sibling tool `aws_wafv2_get_web_acl` (which would retrieve by Web ACL ID/ARN instead of resource association).

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?

While the description implies usage by listing supported resource types (ALB, API Gateway, AppSync), it lacks explicit guidance on when to use this tool versus the sibling `aws_wafv2_get_web_acl`. It does not state prerequisites like requiring the resource ARN format or what to do if no Web ACL is associated.

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