@atengk/mcp-server-s3

stat_object

Retrieve an object's size, Content-Type, last-modified time, ETag, and custom metadata from S3-compatible storage to inspect or verify stored files.

Instructions

提取对象大小、Content-Type、最后修改时间、ETag 及元数据

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "key": "<key>"
    },
    "name": "stat_object"
  }
}

Input Schema

Name	Required	Description	Default
`key`	Yes
`bucket`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Oct 4, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full behavioral burden. It implies a read-only extraction and lists returned attributes, but omits required permissions, behavior for a missing key, bucket defaults, and error or rate-limit characteristics.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence with no filler; each clause names a returned metadata field. Appropriately sized for a simple stat operation.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness2/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no annotations and no output schema, the description partially compensates by listing returned fields. However, input parameters are entirely unaddressed and there is no output structure or error behavior, leaving the definition incomplete for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, with two parameters, key and bucket, completely undocumented in both schema and description. The description adds no input semantics, so an agent cannot tell that key is required or that bucket is optional.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb, 提取, and the resource attributes returned: object size, Content-Type, last modified time, ETag, and metadata. Clear, but it does not differentiate this stat operation from siblings such as get_object_tags or read_object_text.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Implied usage is to retrieve object metadata, but there is no explicit when-to-use guidance, no exclusions, and no named alternative for cases where object content or tags are needed instead.

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