s3_list_objects

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

With no annotations, the description carries the full burden. It discloses the return format (JSON with folders, objects, and is_truncated) and the pagination limit (~1000 keys). This provides useful behavioral context beyond basic input schema.

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 concise sentences: the first states the core operation, the second provides critical details about return format and pagination behavior. No unnecessary words.

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 no output schema and no annotations, the description adequately covers return format and pagination. It does not discuss error conditions or permissions, but for a simple listing tool, this is sufficient.

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%, so the baseline is 3. The description does not add additional meaning to the parameters themselves; it only describes the output. This meets the minimum expectation.

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 explicitly states 'List objects and virtual-folder prefixes in an S3 bucket,' which is a specific verb-resource pair. It clearly distinguishes from sibling tools like s3_list_buckets by focusing on object-level listing rather than bucket enumeration.

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 a clear usage hint: 're-call with a more specific prefix' when is_truncated is true, addressing pagination. However, it does not explicitly state when to use this tool over alternatives like s3_list_buckets or other listing tools.

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