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

The annotations only say this is not read-only, is not destructive, and is closed-world; the description supplies far more: a 15-minute expiry, a 50 MB ceiling, that the transfer is a PUT with the supplied Content-Type, and that the upload_id must then be handed to upload_file. Those operational constraints are exactly the behavior an agent needs and are not derivable from annotations or schema.

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 tight sentences with no filler. The key constraints (one file, 15 minutes, 50 MB) are front-loaded, followed by the exact call sequence, so the agent gets the gating facts before the procedure.

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?

Although there is no output schema, the description effectively reveals the return payload (upload_id plus a Content-Type) by explaining the subsequent PUT and upload_file call. For a single-parameter tool, nothing needed to invoke it correctly is missing.

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% and the single file_name parameter is already documented with an example, so the baseline is high. The description nonetheless adds meaning: the file is expected to be on local disk, and its extension drives the Content-Type used in the PUT, which the schema alone does not convey.

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 names a specific resource ('a one-file upload link') and its operating envelope (15-minute validity, 50 MB cap), and it names the follow-up tool 'upload_file' so the agent can distinguish this link-generation step from the actual upload call. The verb and resource 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?

It gives an explicit condition for choosing this tool: 'for when you can run a command, such as curl -T with the file on disk,' which distinguishes it from a direct upload path. It stops short of stating the excluded case (for example, what to do if you cannot run a command), so it is clear context rather than a full when/when-not rule.

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