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

Annotations already establish the safety profile (mutating, idempotent, non-destructive, closed-world), so the bar is lower. The description adds real workflow context beyond them: results are an immutable draft, other scene definitions are preserved, and the revision must pass review and production approval again. It stops short of explaining how idempotencyKey affects replay behavior, but the added value is genuine.

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 the core action, then constraints. No filler and every sentence carries weight.

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 an output schema present, return values needn't be described, and annotations cover safety semantics. The description covers the mutation's downstream workflow implications, which is the main thing an agent needs. Minor gaps remain around parameter-level expectations for a 9-parameter mutation.

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 only 22%, so the description must compensate, and it partially does by naming the three change categories (scene, character, model) that map to scene_updates, character_updates, and the model-id params. It says nothing about idempotencyKey, workspaceId/projectId scoping, or the per-item update structures, leaving significant gaps.

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 and resource: creating a new immutable draft from a known revision with scene/character/model changes. It also distinguishes itself from a plain storyboard create by emphasizing the revision basis and preservation of other scenes, so an agent can tell it apart from siblings without opening schemas.

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?

The description gives implied when-not boundaries (does not generate media, does not overwrite an approved revision), which steer the agent away from generation and approval flows. However, it never names the alternative tools (e.g. video_storyboard_create, video_storyboard_asset_regenerate, generation_*) or states the positive condition for choosing this tool over them.

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