Find the largest objects in an S3 bucket by scanning up to max_scan keys; partial results include a continuation token for follow-up calls.
Bounded largest objects scan, default max_scan 10000; partial results carry continuation token.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| bucket | Yes | ||
| prefix | No | ||
| max_scan | No | ||
| continuation_token | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It usefully discloses bounded scanning, default max_scan=10000, and that partial results carry a continuation token. However, it omits read-only nature, permissions, cost/latency implications, and whether max_scan counts objects or bytes.
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?
Single compact sentence, front-loaded with the core operation and key constraint. No fluff, but its brevity comes at the cost of missing parameter and usage detail.
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 5-parameter scan with no annotations or output schema, the description is too thin. It omits the roles of bucket, prefix, and limit, the relationship between limit and max_scan, how 'largest' is defined or ordered, and what the response contains.
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 0% across 5 parameters. The description only addresses max_scan and continuation_token, leaving bucket, prefix, and limit undefined, and does not clarify how limit differs from max_scan.
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?
States a specific operation (scan for largest objects) and a key constraint (bounded with default max_scan). It does not differentiate from siblings like s3_list_objects or s3_prefix_usage, which also enumerate bucket contents.
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?
No guidance on when to choose this over s3_list_objects or s3_prefix_usage, nor any prerequisites. The default max_scan and continuation token are parameter behavior, not selection criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.