AWS MCP Server

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

No annotations provided, so description carries full burden. Adds valuable context: specifies 'management events' (not data events) and default 90-day window. Missing: permissions requirements, pagination behavior, read-only nature, and rate limits.

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?

Three efficient sentences with zero waste. Front-loaded with purpose ('Look up...'), followed by filtering capabilities, then default time window. Every sentence 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?

Adequate for a lookup tool with well-documented schema, but gaps remain: no output schema mentioned, no IAM permission requirements specified, and pagination behavior undocumented. Reasonable given input schema richness but could disclose more behavioral constraints.

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 has 100% description coverage, establishing baseline 3. Description adds semantic value by listing example filter categories (event name, resource type, user name) that map to AttributeKey enum values, helping agents understand lookup_attributes construction.

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 ('Look up') and resource ('CloudTrail management events'). Implicitly distinguishes from sibling 'aws_cloudtrail_describe_trails' by focusing on 'events' versus 'trails', though lacks explicit contrast.

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?

Implies filtering use cases ('Filter by event name, resource type, user name, etc.') but lacks explicit 'when to use' guidance versus siblings or alternatives. 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.