Lists the parts already uploaded for a specific multipart S3 upload by bucket, object key, and upload ID. Use it to inspect progress or resume incomplete uploads.
List multipart parts.
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | ||
| bucket | Yes | ||
| max_keys | No | ||
| upload_id | Yes | ||
| 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 behavioral burden, and it discloses nothing: no pagination behavior, no note that results are only meaningful for an active upload, no auth/permission requirements, no error semantics for expired upload IDs.
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 single sentence is short but that brevity reflects under-specification rather than economy. There is no structure, no front-loaded context, and nothing to help an agent act correctly.
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?
With no annotations, no output schema, and 5 completely undocumented parameters, the definition is inadequate for an agent to invoke this tool correctly. It fails to convey required inputs' meaning or expected return shape.
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 0% across 5 parameters (bucket, key, upload_id, max_keys, continuation_token), and the description adds no meaning for any of them. Notably, it never explains that upload_id identifies the upload whose parts are being listed, nor how max_keys/continuation_token drive pagination.
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 'List multipart parts' essentially restates the tool name (s3_list_parts) without adding distinguishing detail. It does not clarify that these are parts belonging to a single in-progress multipart upload, which is the key distinction from the sibling s3_list_multipart_uploads.
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 whatsoever on when to use this tool, what prerequisites exist (a valid upload_id from an in-progress multipart upload), or how it relates to s3_list_multipart_uploads and s3_unfinished_uploads.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.