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 of behavioral disclosure. It successfully indicates the destructive nature ('Delete') and the runtime mode constraint ('--readonly mode'), but lacks details on partial failure handling, idempotency, or irreversibility warnings typical for destructive operations.

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. The first sentence front-loads the core action, and the second sentence provides the critical operational constraint. Every word earns its place with no redundancy.

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 destructive operation with no output schema and no annotations, the description provides minimum viable coverage by stating the action and the readonly constraint. However, it lacks safety context (irreversibility warnings) or return value description that would be expected for a delete tool.

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%, with all four parameters (profile, region, bucket, keys) fully documented in the schema. The description adds minimal semantic value beyond the schema (only implying quantity via 'one or more'), warranting the baseline score of 3.

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 uses a specific verb ('Delete') with clear resource ('objects from an S3 bucket') and scope ('one or more'). It effectively distinguishes from siblings like aws_s3_get_object, aws_s3_list_objects, and aws_s3_put_object through the explicit 'Delete' action.

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 one explicit usage constraint ('Blocked in --readonly mode'), which functions as a when-not-to-use guideline. However, it lacks alternatives or prerequisites (e.g., suggesting verification via list_objects first), keeping it at implied usage guidance rather than comprehensive guidelines.

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