s3_list_objects

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 does not mention pagination behavior, the default maxKeys (100) already exposed in the schema, or any LocalStack-specific quirks. It only states the operation without clarifying return format or potential truncation.

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 a single concise sentence: 'List objects in an S3 bucket in LocalStack'. It is front-loaded with the verb and resource, contains no filler, and every word earns its place.

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 simple list operation, the description is adequate but incomplete. The schema covers parameter defaults and constraints, but the description does not mention return value structure or pagination limits. Without an output schema, users might not know the response format, though the operation type makes it somewhat predictable.

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 coverage is 100%, with each parameter (bucket, prefix, maxKeys) having a clear description. The tool description adds no additional semantic meaning beyond the schema, which is acceptable per the baseline of 3 when schema coverage is high.

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 is specific: 'List objects in an S3 bucket in LocalStack' clearly states the action (list) and resource (objects in an S3 bucket). It distinguishes from sibling tools like s3_list_buckets (lists buckets) and s3_get_object (retrieves a single object), making the purpose 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?

The description provides no guidance on when to use this tool versus alternatives. It does not mention that s3_list_buckets lists buckets or that s3_get_object fetches a single object, nor does it state any prerequisites or exclusions. The user is left to infer usage from the tool name and context.

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