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 but fails to disclose read-only safety, pagination behavior, or that it returns task ARNs rather than full task details. The mention of 'optional' filters is the only behavioral hint.

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 front-loaded sentence with no redundancy. Efficient but arguably too terse given zero annotations and lack of output schema—it sacrifices necessary behavioral context for brevity.

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?

Minimum viable for a list operation: identifies resource and filtering. However, with no output schema and no annotations, it should describe the return value (task ARNs) and potentially pagination limits. Adequate but leaves important operational context to trial and error.

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%, so the structured data documents all 5 parameters adequately. The description adds semantic grouping ('service or status filter') matching the enum and optional params, but does not add syntactic details or format constraints beyond 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?

Clearly states the resource (ECS tasks) and container (cluster) with specific verb 'List'. Distinguishes from sibling list_clusters and list_services by specifying 'tasks', though it omits the critical distinction from aws_ecs_describe_tasks (that this returns task ARNs/IDs while describe requires them as input).

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?

Mentions optional filters but provides no guidance on when to use versus aws_ecs_describe_tasks or prerequisites like cluster existence. No explicit workflow guidance or error handling context.

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