MinIO MCP Server

minio_put_object

Upload text content as an object to a MinIO bucket with specified bucket name, object name, and optional MIME type for object storage management.

Instructions

Upload content as an object to MinIO bucket

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": {
      "bucket_name": "<bucket_name>",
      "object_name": "<object_name>",
      "content": "<content>"
    },
    "name": "minio_put_object"
  }
}

Input Schema

Name	Required	Description
`bucket_name`	Yes	Name of the bucket
`object_name`	Yes	Name for the object in the bucket
`content`	Yes	Text content to upload
`content_type`	No	MIME type of the content (default: application/octet-stream)

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Mar 9, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations provided, the description carries full burden for behavioral disclosure. While 'Upload' implies a write operation, it doesn't specify permissions required, whether it overwrites existing objects, error conditions, or any rate limits. For a mutation tool with zero annotation coverage, this leaves significant behavioral gaps.

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?

The description is a single, efficient sentence that states the core purpose without any unnecessary words. It's appropriately sized for a straightforward upload operation and gets directly to the point.

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?

For a mutation tool with no annotations and no output schema, the description is insufficient. It doesn't explain what happens on success/failure, return values, error conditions, or how it differs from similar sibling tools. Given the complexity of object storage operations and the rich sibling toolset, more context is needed.

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

Parameters3/5

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

Schema description coverage is 100%, so all parameters are documented in the schema. The description doesn't add any additional parameter semantics beyond what's already in the schema descriptions. The baseline of 3 is appropriate when the schema does the heavy lifting for parameter documentation.

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?

The description clearly states the action ('Upload content') and target ('as an object to MinIO bucket'), which is specific and unambiguous. However, it doesn't differentiate from sibling tools like 'minio_upload_file' or 'minio_copy_object', leaving some ambiguity about when to choose this specific upload method.

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus alternatives like 'minio_upload_file' or 'minio_copy_object'. There's no mention of prerequisites, constraints, or typical use cases that would help an agent choose between these similar upload/creation tools.

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

Deploy Server