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 successfully discloses the data source (local AWS config files) and return structure (profile names + default regions). Could mention that it's read-only/safe, but the file paths provide substantial behavioral context.

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, zero waste. First sentence establishes operation and data source; second sentence covers return values. Perfectly front-loaded for a schema-less tool.

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?

Appropriate for a simple 0-parameter utility. Since no output schema exists, the description compensates by explicitly stating what gets returned (profile names and regions). Would be 5 if it mentioned error handling (e.g., missing config files).

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?

Zero parameters present; per rubric baseline is 4. The description correctly implies no inputs are needed by focusing entirely on the operation and return values.

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?

Excellent specificity: 'List all AWS profiles' provides clear verb and resource, and '(from ~/.aws/config and ~/.aws/credentials)' distinguishes this local config reader from the numerous AWS API operational siblings (ec2, s3, etc.). The scope is unambiguous.

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?

Lacks explicit when-to-use guidance or mention that this is a prerequisite for profile-aware AWS operations. However, the local-vs-API distinction is clear enough that an agent can infer usage. No explicit alternatives or prerequisites stated.

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