AWS MCP Server

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

Annotations already provide readOnlyHint=true, idempotentHint=true, and destructiveHint=false, which cover the safety profile. The description adds no behavioral context beyond what annotations provide - no information about pagination behavior (implied by NextToken parameter), rate limits, authentication requirements, or what constitutes a successful response. However, it doesn't contradict the annotations.

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?

The description is maximally concise with just two words. While this represents under-specification rather than ideal conciseness, it contains no wasted words and is perfectly front-loaded. Every word (both of them) serves the core purpose statement.

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 tool with 8 parameters (within AmiArgs), no output schema, and complex filtering capabilities, the description is severely inadequate. It doesn't explain what AMIs are, what information is returned, how results are structured, or any behavioral characteristics beyond what annotations provide. The agent would struggle to use this tool effectively based solely on the description.

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?

With only 50% schema description coverage, the description fails to compensate for the gaps. 'List AMIs' provides zero information about parameters, while the schema documents 8 parameters within AmiArgs. The description doesn't explain what filtering options exist, what Owners means, or how pagination works. This leaves significant parameter semantics undocumented.

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 'List AMIs' is a tautology that merely restates the tool name without adding meaningful context. It doesn't specify what AMIs are (Amazon Machine Images) or clarify the scope of the listing operation. While the verb 'List' is clear, the description fails to distinguish this tool from other list tools like list-ec2-instances or list-buckets.

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?

The description provides absolutely no guidance about when to use this tool versus alternatives. It doesn't mention that this is for retrieving AMI metadata, nor does it explain relationships with sibling tools like create-ami or delete-ami. There's no context about prerequisites, permissions, or typical use cases.

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