AWS MCP Server

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

No annotations are provided, leaving the description to carry full behavioral disclosure. It fails to indicate this is a read-only operation, mention required IAM permissions (s3:ListAllMyBuckets), note rate limiting concerns, or describe the return structure (bucket names, creation dates, regions). Only behavioral hint is 'in the account' which defines scope.

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?

Single sentence with zero wasted words. Information density is high relative to length; every word serves to define the operation's scope and target.

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 enumeration tool with complete input schema coverage. However, lacking both annotations and output schema, the description should compensate with behavioral context (permissions, return format) which it does not provide. Acceptable but clearly incomplete.

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%, with both profile and region well-documented in the schema itself. The description adds no parameter-specific context (e.g., when to override region, how profile maps to ~/.aws/config), warranting the baseline score for high-coverage schemas.

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?

States specific verb (List) and resource (S3 buckets) with clear scope ('in the account'). Implicitly distinguishes from sibling aws_s3_list_objects by targeting buckets versus objects, but does not explicitly name the alternative or clarify account-level vs. bucket-level operations.

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 no guidance on when to use this tool versus other S3 operations (like aws_s3_list_objects) or when to specify the optional profile/region parameters versus relying on default credentials. No prerequisites or exclusions mentioned.

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