AWS MCP Server

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

With no annotations provided, the description carries the full burden. It adds the critical behavioral constraint about --readonly mode blocking, but omits other important behavioral details like return values (e.g., MessageId), message size limits, or failure modes.

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?

Two sentences with zero waste: the first establishes purpose, the second states a critical runtime constraint. Every word earns its place and the description is appropriately front-loaded.

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?

Given the 100% schema coverage, the description meets minimum viability, but gaps remain for a write operation: no output schema description, no mention of SQS-specific constraints (256KB limit, FIFO requirements), and no differentiation from sibling messaging tools.

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?

The input schema has 100% description coverage, establishing a baseline of 3. The description adds no additional parameter semantics (e.g., syntax examples, validation rules) beyond what the schema already provides.

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?

The description states the specific action ('Send a message') and target resource ('SQS queue'), clearly distinguishing it from siblings like aws_sqs_receive_message, aws_sqs_purge_queue, and aws_sqs_list_queues.

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?

It provides one constraint ('Blocked in --readonly mode'), indicating when the tool cannot be used, but lacks positive guidance on when to use this vs. alternatives like aws_sns_publish or aws_lambda_invoke for messaging.

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