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

Annotations already declare readOnly/idempotent/non-destructive, so safety is covered. The description adds genuinely useful output-behavior detail ('Transition names are normalized to content-motion semantics') and describes the read receipt, though 'Reading a translation does not change it' largely restates the readOnly hint.

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 tight sentences, front-loaded with what is returned. Some phrasing is jargon-heavy ('same-target editing read receipt', 'content-motion semantics') but each sentence carries 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?

An output schema exists so return shape needn't be fully spelled out, and the safety profile is in annotations. However, for a 4-param tool with a rich set of promo-video siblings, the absence of any selection guidance leaves a real gap.

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 75% and the schema itself documents language, projectId, and generationId with usage notes. The description adds no parameter-level meaning (e.g. nothing about variantId, the only undescribed param), so baseline 3 is appropriate.

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 uses a specific verb (Returns) and resource (saved promo-video configuration) and enumerates the payload (configuration, source/available languages, editing read receipt). It is clear what the tool does, but it does not distinguish itself from close siblings like get_promo_video_generation or preview_promo_video.

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?

There is no explicit when-to-use or when-not guidance, and no mention of the obvious alternatives (get_promo_video_generation, preview_promo_video, get_promo_video_export). 'Reading a translation does not change it' implies a read context but doesn't route the agent between tools.

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