AWS MCP Server

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

No annotations provided, so description carries full burden. It discloses what data is returned (agent status, platform info) but omits operational details like read-only safety, pagination behavior with max_results, or AWS rate limiting characteristics.

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 waste. Front-loaded with action verb, resource clearly identified, and value proposition (agent status/platform info) included efficiently. No redundancy or filler text.

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?

Appropriate for a standard AWS describe operation with 100% schema coverage and 4 parameters. Mentions key return data fields despite missing output schema. Could improve by explicitly stating read-only nature or pagination behavior, but sufficient for agent selection.

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%, establishing baseline 3. Description adds minimal parameter context beyond schema, though 'List' verb implicitly supports the filters and max_results parameters. No additional syntax or format guidance provided.

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' with clear resource scope 'EC2 instances managed by SSM' and specifies returned data 'agent status and platform info'. Effectively distinguishes from aws_ec2_describe_instances (general EC2) and other SSM tools like describe_parameters.

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 implied usage context through 'managed by SSM' qualifier, suggesting when to use this over general EC2 describe operations. However, lacks explicit when/when-not guidance or named alternatives for cases requiring different instance filtering.

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