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

The annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context by stating that it returns new one-hour links after expiry, though it does not discuss auth/rate-limit behavior or error cases.

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?

The description is two concise sentences with zero waste. The core purpose and return behavior are front-loaded, followed by the necessary parameter guidance.

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?

It covers the purpose, usage condition, return link lifetime, and most parameters, which is substantial for a nested-schema tool with no output schema. It is still incomplete because it does not mention the required serverId parameter or explain how the nested path and body fit together.

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?

The description names jobId, uploadId, key, and the pieces still to upload, which maps meaning onto most inputs and clarifies that partNumbers are expired pieces still needing upload. However, it omits the required serverId path parameter and does not clarify the nested path/body structure, which matters given the nested schema.

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: it returns new one-hour links for pieces of a startWorldUpload whose links expired. It clearly distinguishes this operation from startWorldUpload and completeWorldUpload by focusing narrowly on renewing expired part links.

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 clearly says when to use the tool: for pieces still to upload whose links have expired. It does not name explicit alternatives or when-not conditions, but the lifecycle context is strong enough for an agent to infer correct use.

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