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

The description discloses the internal mechanism: base64-encoding, chunked writes through terminal session, and md5 checksum verification. This is valuable because it explains why this tool is more reliable for large files (exec channel fragility). Since no annotations exist, this carries the full burden, and it does well in explaining behavior beyond the basic action.

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?

Two sentences, no waste. The core purpose is stated first, then the mechanism and usage guidance. Efficient and well-structured.

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?

For a tool with 5 parameters and no output schema, the description covers the key behavioral aspects (chunked upload, verification) and gives a clear use case. It could mention the requirement of an active session (implied by 'terminal session') and the return value, but these are minor given the schema already specifies workspace_id and the tool's nature.

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 coverage is 100%, so parameters are already documented. The description adds no additional parameter-specific details. It provides context about the upload process but not about the parameters themselves. Thus, it meets the baseline but doesn't exceed it.

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 clearly states the action: 'Upload a local file into the sandbox workspace.' It also hints at differentiation by saying 'Use this instead of embedding large file content directly in a command,' which helps distinguish from command execution tools. However, it doesn't explicitly differentiate from huaweicloud_sandbox_upload_project, but the singular 'file' vs project is implicit.

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?

It provides a specific usage condition: for large file content, don't embed in command, use this upload. This is a clear when-to-use. It doesn't explicitly mention alternatives like upload_project, but it gives a context for when this tool is preferred over direct command execution. It lacks explicit exclusions or a comparison with other sandbox tools.

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