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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety burden is off the description. The description still adds value by disclosing the result composition (14 built-ins plus workspace saved styles) and the ordering, which annotations cannot express.

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 short sentences, front-loaded with the primary statement of what is listed, followed by the practical consumption note. No filler or repeated information from annotations.

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 no explanation here. The description covers scope, ordering and how to use the results; the only missing piece is differentiation from the sibling motion-sequences tool.

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?

The tool takes zero parameters, so the baseline is 4. The description does go slightly beyond the empty schema by explaining that returned ids are consumed via videoSettings.motionStyle, which connects this tool's output to another tool's input.

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 ('List the motion styles a video can take') and specifies the composition of the result: 14 built-ins followed by workspace-saved styles. It does not, however, distinguish itself from the sibling postnitro_list_motion_sequences, which an agent could easily confuse with this tool.

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 closing sentence 'Pass an id as videoSettings.motionStyle' tells the agent how to consume a returned id, which is genuine downstream guidance. It gives no when-to-use guidance relative to alternatives such as postnitro_list_motion_sequences or postnitro_list_ai_presets, so the selection logic is left implicit.

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