Reads a specific byte range of an object from S3-compatible storage, enabling troubleshooting of large objects and inspection of object headers.
HTTP Range 字节范围读取（适用于大对象末尾排障与对象头检视）
| Name | Required | Description | Default |
|---|---|---|---|
| key | Yes | ||
| bucket | No | ||
| end_byte | Yes | ||
| start_byte | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full behavioral burden. It discloses the HTTP Range mechanism (implying a read-only, partial read) and intended use cases, but omits permissions, rate limits, error behavior, and return format details.
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?
A single sentence with no wasted words, front-loading the core action and following with a compact use-case clause. It is appropriately sized for a tool description, even if it omits details better handled elsewhere.
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 4 parameters, 0% schema description coverage, no annotations, and no output schema, the description should explain parameter semantics and basic behavior. It only provides purpose and two use cases, leaving critical invocation details absent.
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 mention any parameter by name. 'Byte range' loosely implies start_byte and end_byte, but key and bucket are completely undocumented, so the description fails to compensate for the coverage gap.
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: 'HTTP Range byte range read'. It also adds two use cases (large object tail troubleshooting and object header inspection) that hint at when this differs from a full-object read, but it never names sibling tools like read_object_text or download_file.
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 parenthetical explicitly says the tool is suitable for large object tail troubleshooting and object header inspection, giving clear context for when to use it. It does not provide exclusions or name alternatives, so it falls short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.