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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds meaningful context beyond that: despite the action verb 'prepare', it explicitly will not connect to a TV or start playback, clarifying the scope of the side effect. It stops short of describing what the 'Cast workflow' actually entails.

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, zero filler, with the positive purpose front-loaded and the limiting boundary immediately after. Nothing is wasted.

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 values need not be explained, and annotations cover safety. That leaves the poorly documented parameters (0% schema coverage) as the main gap, which the description does not fill, making it only minimally complete for a tool with an ambiguous 'prepare' action.

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 description coverage is 0%, so the description carries the full burden of explaining the three parameters. It never explains slug, the one/series 'mode' enum, or the 'edition' integer; the only hint is the phrase 'artwork or series', which loosely maps to mode. This leaves two of three parameters undocumented anywhere.

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 ('Prepare') and resource ('verified artwork or series display URL and existing mobile Cast workflow'), so the agent knows it produces a URL plus a Cast workflow. It does not differentiate itself from the sibling get_artwork, which is the nearest alternative, so it falls short of a 5.

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?

'Does not connect to a TV or start playback' functions as an explicit when-not boundary, which is useful. However, there is no positive guidance on when to choose this over get_artwork or what prerequisite (a verified artwork) must hold; usage is only implied.

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