s3_list_objects

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

With no annotations, the description fully discloses return structure (folders, objects with metadata, is_truncated), the ~1000 key truncation limit, and the recommended follow-up action. This goes beyond basic semantics and gives the agent actionable behavioral context for handling large result sets.

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 fluff. The first sentence states the tool's function, the second explains output shape and truncation behavior. Every clause carries value, and the structure is front-loaded with the core purpose.

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, the description adequately covers return format, pagination/truncation, and grouping. It lacks error handling details (e.g., missing bucket, permission errors) and sorting semantics, but for a read-only list tool this is sufficient for correct invocation.

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 already described. The description adds only indirect context about the prefix parameter's role in truncation handling, but does not introduce new parameter-specific meaning beyond the schema. Baseline score of 3 applies.

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 clearly states the tool lists objects and virtual-folder prefixes in an S3 bucket, using a specific verb ('List') and resource. It distinguishes itself from sibling s3_list_buckets by focusing on bucket contents 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 gives implicit guidance on when to use this tool (listing bucket contents) and provides an explicit usage note: when is_truncated is true, re-call with a more specific prefix. It does not explicitly mention alternatives like s3_download_object, but the purpose is clear enough to avoid confusion.

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