AWS MCP Server

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

With no annotations provided, the description carries full burden. It discloses the optional event bus scoping behavior, but lacks critical safety disclosure (read-only vs. mutating), pagination behavior implied by 'limit' parameter, return value structure, or AWS rate limit considerations.

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, nine words. Immediately actionable verb placement, zero redundancy. Efficiently conveys core purpose without extraneous content.

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?

For a 5-parameter list operation with 100% schema coverage and simple types, the description is minimally adequate. However, given absence of annotations and output schema, it should explicitly state read-only safety and distinguish from the 'describe' sibling to be complete.

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 of 3. Description adds semantic context that event bus filtering is optional ('optionally'), aligning with the default behavior documented in schema, but does not elaborate on parameter interactions or input formats beyond 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?

States specific verb (List) and resource (EventBridge rules) clearly. Mentions optional event bus filtering. However, fails to distinguish from sibling 'aws_events_describe_rule' which likely retrieves single rule details vs. this listing operation.

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 versus 'aws_events_describe_rule' for detailed single-rule inspection, or when to use 'aws_events_list_event_buses' to discover buses first. No mention of prerequisites or typical workflows.

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