Retrieve an object from any S3-compatible bucket using its key. Returns UTF-8 text or base64-encoded content automatically.
Read an object. UTF-8 content returns as text; anything else as base64.
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | ||
| bucket | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotation readOnlyHint=true already establishes that this is a safe read operation. The description adds valuable behavioral context by explaining how content is returned: UTF-8 as text, otherwise base64. This goes beyond the annotation and helps the agent interpret the response.
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 description is appropriately short and front-loaded. The core action appears first, followed by a concise behavioral note. Every sentence earns its place with no wasted words.
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 the simple two-parameter input, the readOnly annotation, and the presence of an output schema, the description covers the most relevant invocation detail: response encoding. It is slightly incomplete in lacking usage guidance, but it is adequate for a straightforward read operation.
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%, and the description does not explain the meaning or usage of bucket or key. The parameter names are somewhat self-explanatory, but the description adds no semantic detail to help an agent construct correct arguments.
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 states a specific verb and resource: "Read an object." This clearly distinguishes it from sibling tools like put_object, delete_object, and list_objects. The action and target are unambiguous.
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 provides no guidance on when to use this tool over alternatives such as stat_object or presign_get. It does not mention exclusions, prerequisites, or when another sibling would be more appropriate.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.