Upscale a finished video (new job)

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

With no annotations, the description carries the full burden and mostly does: it discloses non-destructiveness (original preserved), a concrete cost (0.2 credits per second), model-specific constraints, and the polling workflow. It does not mention authentication, rate limits, or failure behavior, which keeps it from a 5.

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?

Dense and front-loaded: the primary behavior, then model-specific rules, then cost, then the next step. Every fragment adds information. The telegraphic style ('craftstory-2: ...', 'minimax-h3: ...') is compact but slightly terse, requiring careful parsing.

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?

For a 3-parameter tool with no output schema and no annotations, the description covers the essential behavioral facts: cost, non-destructiveness, model constraints, and polling follow-up. It omits return-value specifics beyond the job id and any error or retry semantics.

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 33%, so the description must compensate, and it does: it explains that resolution applies only to craftstory-2 and maps the enum values to source resolutions (1080_1920 from 720_1280, etc.), plus that minimax-h3 needs no resolution. The 'id' parameter is only implied via 'Poll the returned id' rather than explicitly defined as the source or job identifier.

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 ('Creates a NEW job with the upscaled result') and immediately clarifies the non-destructive nature ('the original stays'), distinguishing it from create_craftstory2_video / create_minimax_h3_video siblings which generate rather than upscale.

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?

Provides per-model guidance: which models need a resolution, which resolutions are valid for craftstory-2, and that minimax-h3 is always 2x so 'no resolution needed'. Also routes to wait_for_job for polling. It stops short of an explicit when-to-use-this-vs-alternatives statement (e.g. when upscaling is preferable to regenerating).

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