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

With no annotations, the description carries the full behavioral burden and delivers substantially: short-lived link, 2 GB ceiling, 95 MB per-request limit, offset-based chunking, response `next_offset`, the destructive 'offset 0 overwrites' behavior, and prerequisites (token + live sandbox_id). Gaps remain around TTL/link expiry semantics and failure modes, which keeps it from a 5.

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?

Purpose is front-loaded and the operational details are dense and mostly earned, but the trailing '≤95 MB per PUT; use ?offset for more' restates the earlier 'One request carries at most 95 MB' and the offset instruction, adding redundancy to an already long single paragraph.

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 multi-step chunked-upload tool with no output schema and no annotations, the definition covers the mechanics unusually well, including the `next_offset` return signal. Missing pieces are minor: the ttl parameter's meaning and what an expired or failed link yields are not addressed.

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 only 25% (just sandbox_id), so the description must compensate. It explains `path` implicitly, maps 'up to 2 GB' onto max_bytes, and clarifies upload semantics, but `ttl` is only hinted at by 'short-lived' and never defined, and the 60–3600 range is undocumented in either place.

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 first clause states a specific verb and resource: 'Get a short-lived HTTPS link to PUT ONE file into the sandbox at `path` (up to 2 GB)'. Scope and size bound are explicit, so the agent immediately knows this returns a URL for out-of-band upload rather than uploading content itself. It never names the sibling `upload_file` or any alternative, so it stops short of full sibling differentiation.

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 gives rich operational how-to (curl -fT, 95 MB chunks, ?offset ordering, offset 0 overwrites) which tells the agent *how* to consume the URL, and 'No base64 through this conversation' hints at the intended out-of-band scenario. However, it never states when to pick this over `upload_file` or any other transfer path, so alternative selection is left to inference.

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