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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds genuinely useful context beyond that: link lifetime ('files live about 2 h') and the assurance that no re-render work is triggered. It does not describe the returned fields, but the annotations carry most of the behavioral burden.

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 trigger-first opening is well front-loaded and the prose is dense rather than padded. However, the trailing 'Schema 3b8fe45c' is pure filler that repeats the schema's own description field and dilutes the useful 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?

With two parameters and no output schema, the description needs to say what comes back, and 'links or status' covers the shape at a high level, plus a useful expiry note. It stops short of naming the concrete response fields, but the agent has enough to act.

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 50%, so the description must compensate, and it largely does: 'pass the asset ids from the result' explains where ids come from and 'Optional hash check' maps to the verify parameter. It omits the 16-item cap on ids and gives no hint about the sha256 detail beyond the 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 concrete outcome: pass asset ids to get download links or render status back, explicitly without re-rendering. Combined with the title 'Renew download links' the verb and resource are clear, though the bare tool name 'assets' does not convey it on its own.

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 explicit triggers ('link was lost or is about to expire, or a render is still rendering') and rules out the expensive alternative with 'no re-render'. It does not name a sibling tool directly, so the agent must infer which tool would otherwise be used.

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