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

Annotations already supply idempotentHint, readOnlyHint, and destructiveHint, so the safety profile is covered. The description adds 'asynchronous,' which is a meaningful operational trait, but it does not disclose the job lifecycle, required terms acceptance, or what the caller should do after submission. No contradiction with annotations.

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?

The description is a single front-loaded sentence with no filler or redundancy. It earns its place, though it is very brief relative to the complexity of the tool. Structure is clean and immediately scannable.

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?

Given 10 parameters, 6 required, multiple legal-acceptance flags, and asynchronous behavior, this description is incomplete. It does not mention that accept_terms, accept_retention, and accepted_terms_version are mandatory, nor does it explain how to use idempotency_key or check the resulting animation via sibling get tools. The output schema may cover return values, but the operational context is still insufficient.

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 10%, so the description bears heavy responsibility for explaining parameters. It adds minimal semantic value by indicating the image should be base64-encoded line art, but it says nothing about speed, show_hand, order_text, idempotency_key, installation_id, or the required consent/terms parameters.

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 and resource: 'Create an asynchronous animation from a base64-encoded line-art image.' It clearly names the action and input format, and the word 'Create' distinguishes it from the sibling get/delete/download tools. This is immediately clear and not a tautology.

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?

Usage is only implied by the verb 'Create' and the presence of sibling tools like get_scribe_animation and delete_scribe_animation. There is no explicit statement of when to use this tool versus alternatives, no exclusion criteria, and no mention of prerequisite steps such as accepting terms.

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