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

Annotations already declare a safe, non-destructive read in a closed world, so the bar is lower; the description still adds real value by disclosing the 30-minute link validity, the mp4 format, and the zero-credit cost. It stops short of stating whether regenerating invalidates prior links.

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?

Three short sentences with no filler: the resource and link lifetime lead, kind semantics follow, and the user-facing instruction and cost note close. Every sentence carries distinct information.

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?

An output schema exists, so return-value details are correctly omitted, and the description covers lifetime, format, and cost for a simple two-parameter read tool. The only missing piece is a precondition that the referenced asset be finished, which the wording implies but never asserts.

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% with an enum on kind, so the schema already documents both parameters and their defaults. The description restates the kind values and default, adding only the semantic mapping of each kind to an asset type, which is marginal over 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?

States a specific verb+resource (get a download link) and enumerates exactly which assets it applies to (completed clip, finished video, story episode) plus the output format (mp4). It does not explicitly contrast itself with the sibling get_video/get_clip, so sibling differentiation is left to inference.

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?

Gives a handling instruction ("Show it to the user") and a cost note ("Costs no credits"), which implies usage context, but it never says when to prefer this over get_video or list_videos, nor any precondition such as the clip needing to be completed.

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