sandbox_upload_url

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

No annotations are provided, so the description carries full burden. It discloses that the tool returns a presigned URL (a temporary, secure URL) and that a subsequent POST request is needed. This is good transparency for a non-destructive tool, though it could mention whether the URL expires or the sandbox state is unaffected.

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, each earned: first states purpose, second gives immediate usage instruction. No extraneous content.

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 tool's simplicity (2 params, no output schema, no nested objects), the description is complete enough to guide an agent. It covers the primary action and follow-up HTTP request, though it could clarify the response format or that the URL is only valid for a short time.

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 baseline is 3. The description adds value by implying the 'path' parameter defaults to '/home/user' (not explicitly in schema). The description does not add detail about the sandboxId, but the schema covers it sufficiently.

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 tool gets a presigned URL for uploading a file to a sandbox, using a specific verb ('Get') and resource. It distinguishes from siblings like sandbox_download_url and sandbox_get_url by mentioning the upload intent, but could more explicitly contrast these.

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 includes 'Send a POST request with the file as multipart/form-data to the returned URL', which provides a brief usage hint. However, it does not specify when to use this vs. other upload methods (e.g., sandbox_file_write) or any prerequisites (e.g., sandboxId must reference an active sandbox).

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